Веб-почта: левое меню вровень с панелью — sticky top 96 → 80 px

Без прокрутки меню стоит на ~86 px, а sticky top-24 (96 px) сдвигал его ниже панели.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,9 @@
+.git
+.idea
+.vscode
+**/node_modules
+**/build
+**/dist
+**/.gradle
+**/.angular
+*.log

.drone.yml

@@ -0,0 +1,47 @@
+# Docker image of reactive-mail-server — like htop-web: Drone builds backend/Dockerfile,
+# master pushes it to the Gitea container registry of jambotron.com.
+#   pull request  -> build only (image is not pushed)
+#   push master   -> gitea.jambotron.com/jambotron_gang/reactive-mail-server:latest and :<commit 8>
+# Drone secrets of this repo: REGISTRY_USERNAME, REGISTRY_PASSWORD (Gitea user with write:package in jambotron_gang)
+kind: pipeline
+type: docker
+name: build-test
+
+trigger:
+  event:
+    - pull_request
+
+steps:
+  - name: build-test
+    image: plugins/docker
+    settings:
+      dockerfile: backend/Dockerfile
+      context: .
+      repo: gitea.jambotron.com/jambotron_gang/reactive-mail-server
+      dry_run: true
+---
+kind: pipeline
+type: docker
+name: build-and-push
+
+trigger:
+  event:
+    - push
+  branch:
+    - master
+
+steps:
+  - name: build-and-push
+    image: plugins/docker
+    settings:
+      dockerfile: backend/Dockerfile
+      context: .
+      registry: gitea.jambotron.com
+      repo: gitea.jambotron.com/jambotron_gang/reactive-mail-server
+      tags:
+        - latest
+        - ${DRONE_COMMIT_SHA:0:8}
+      username:
+        from_secret: REGISTRY_USERNAME
+      password:
+        from_secret: REGISTRY_PASSWORD

.gitignore

@@ -1,6 +1,7 @@
 # Java / Gradle
 *.class
 *.jar
+!gradle/wrapper/gradle-wrapper.jar
 *.war
 *.ear
 *.log
@@ -46,3 +47,9 @@ dkim-keys/
 # Environment variables
 .env
 .env.local
+
+# local data of the dev server
+backend/attachments/
+backend/dkim-keys/
+attachments/
+dkim-keys/

README.md

@@ -1,440 +1,207 @@
-# Mail Server
+# Reactive Mail Server
 
-Прототип почтового сервера на **Spring Boot + Angular** с REST API для управления письмами.
+Почтовый сервер на **Spring Boot WebFlux + R2DBC (PostgreSQL) + Angular**: свой SMTP-сервер на Reactor Netty, веб-почта, очередь отправки, DKIM/SPF/DMARC.
 
-## Архитектура
+Назначение — наша настоящая почта **https://mail.jambocheck.com** (prod Jambotron, системная ВМ, адрес `103.109.235.154`) и тестовый проект на Jambotron.
+
+## Забыл пароль — где взять
+
+**Регистрации нет:** ящики создаёт администратор `admin@jambocheck.com` — веб-почта → Настройки → **MAILBOXES**.
+
+**Администратор:** `admin@jambocheck.com`, пароль `eK-6oj3TMtZgoXVxlvtCWFI6` (начальный, записан 2026-11-07 по решению владельца; сменили — обновить здесь).
+
+Пароли остальных ящиков (`staging@`, `no-reply@`, `monitor@`) — в репозитории Jambotron: `INFRASTRUCTURE/SECRETS.md`, раздел «Почта mail.jambocheck.com».
+
+| Ситуация | Что делать |
+| :--- | :--- |
+| Пароль `admin@` ещё не меняли | файл `/app/data/initial-passwords.txt` **внутри контейнера** `mail` на ВМ почты (в этом репозитории его нет; лежит в томе `data`, передеплой его не стирает). С компьютера: `ssh root@103.109.235.150`, затем `incus exec --project jambotron-prod incust-prod-react-mail-server -- docker exec jambotron-109cf3bb-mail-1 cat /app/data/initial-passwords.txt`. В логе `mail` строка `Mailbox created…` есть **только до первого передеплоя** |
+| Пароль `admin@` сменили и забыли | новый пароль прямо в базе почты, ящик и письма остаются — попросить α/Ω; команда — Jambotron, `INFRASTRUCTURE/test-stands.md`, раздел «Почта mail.jambocheck.com» |
+| Забыт пароль другого ящика (`staging@`, `no-reply@`, `monitor@`, свой) | войти под `admin@` → Настройки → MAILBOXES → ключик у ящика → новый пароль (показывается один раз) и вписать его туда, где ящик настроен |
+
+Всё о prod-почте (порты, DNS, кто через неё шлёт) — Jambotron, `INFRASTRUCTURE/test-stands.md`.
+
+## Как устроено
 
 ```
-┌─────────────────────────────────────────────────────┐
+ SMTP-клиент / чужой сервер ──► SmtpServer (Netty, порт 3025) ──┐
-│                    Angular Frontend                  │
+                                                               ├─► MailRouter ─┬─► LocalDelivery → свой ящик (PostgreSQL)
-│  (веб-почта: список, чтение, написание, контакты)    │
+ Веб-почта (Angular) ──► REST /api ──► SubmissionService ──────┘               └─► OutboundQueue → DeliveryWorker → SMTP получателя
-└──────────────────────┬──────────────────────────────┘
-                       │ REST API (JSON)
-┌──────────────────────▼──────────────────────────────┐
-│                  Spring Boot Backend                  │
-│  ┌────────────┐  ┌────────────┐  ┌──────────────┐  │
-│  │  Users     │  │  Messages  │  │  Contacts    │  │
-│  └────────────┘  └────────────┘  └──────────────┘  │
-│  ┌────────────┐  ┌────────────┐                      │
-│  │  Folders   │  │Attachments │                      │
-│  └────────────┘  └────────────┘                      │
-│                       │                               │
-│              ┌────────▼────────┐                      │
-│              │  JavaMailSender │                      │
-│              │  (SMTP отправка)│                      │
-│              └─────────────────┘                      │
-└──────────────────────┬──────────────────────────────┘
-                       │ JPA
-┌──────────────────────▼──────────────────────────────┐
-│                  PostgreSQL 17                        │
-└─────────────────────────────────────────────────────┘
 ```
 
-## Запуск
+- **Приём (SMTP).** Команды разбираются по строкам (`LineBasedFrameDecoder`): работает и пачка команд в одном пакете, и строка, разорванная на два пакета. Письмо сохраняется или ставится в очередь **до** ответа `250`; если сохранить не удалось — `451`, и отправитель повторит. Работа с базой и DNS идёт не в сетевом потоке.
+- **TLS.** `STARTTLS` на порту SMTP (RFC 3207) и, если задан `SMTPS_PORT`, неявный TLS (RFC 8314, обычно 465); TLS 1.2/1.3. После `STARTTLS` сессия начинается заново (новый `EHLO`), а команды, присланные открытым текстом вместе со `STARTTLS`, не выполняются — соединение закрывается (CVE-2011-0411). `AUTH` предлагается только внутри TLS (или без него при `SMTP_AUTH_WITHOUT_TLS=true`). Сертификат — свой (`MAIL_TLS_CERT` + `MAIL_TLS_KEY`, например Let's Encrypt) или самоподписанный: создаётся один раз в `MAIL_TLS_DIR` и потом переиспользуется. Свой сертификат сервер перечитывает сам, когда файлы меняются (проверка раз в минуту): обновлённый Let's Encrypt подхватывается без перезапуска, недописанный файл не ломает TLS — остаётся прежний сертификат.
+- **Не открытый релей.**
+  - Письмо на свой домен принимается от кого угодно.
+  - Письмо на чужой домен — только после `AUTH`, иначе `550 5.7.1 Relaying denied`.
+  - Вошедший пользователь пишет только от своего адреса, иначе `553`.
+- **Маршрут** (`MailRouter`) один для SMTP и веб-почты:
+  - есть такой ящик в нашем домене → в него;
+  - задан `MAIL_CATCH_ALL` → всё остальное (и чужие домены) — в ящик-ловушку, наружу ничего;
+  - наш домен без такого ящика → «нет такого пользователя»;
+  - чужой домен → очередь.
+- **Отправка наружу** (`OUTBOUND_MODE`):
+  - `off` — ничего не уходит;
+  - `mx` — напрямую на MX получателя, порт 25, STARTTLS по возможности;
+  - `smarthost` — через провайдера (Resend, SES) с логином и проверкой TLS.
+  - **Очередь** — таблица `outbound_queue`. Временная ошибка — повтор через 1 мин, 5 мин, 15 мин, 1 ч, 3 ч, 6 ч, 12 ч. Постоянная ошибка или исчерпанные повторы — уведомление отправителю во входящие.
+- **DKIM.** Подпись — `utils-mail-dkim` (rsa-sha256, relaxed/relaxed), проверка входящих — Apache James jDKIM по ключу из DNS отправителя. Ключ создаётся один раз в `DKIM_KEYS_DIR`, запись для DNS печатается в лог при старте: `TXT <selector>._domainkey.<domain>`.
+- **Права.** Письма, папки и вложения отдаются только владельцу (чужие — `404`). Регистрация по умолчанию закрыта, ящики — только в своих доменах.
 
-### 1. Docker Compose (рекомендуется)
+## IMAP
+
+Почтовые программы (Thunderbird, почта на телефоне) работают с теми же ящиками, что и веб-почта.
+
+- **Порт** `IMAP_PORT` (3143) со `STARTTLS`, и неявный TLS на `IMAPS_PORT` (993), если задан. Сертификат тот же, что у SMTP. Вход (`LOGIN`, `AUTHENTICATE PLAIN`) — только внутри TLS, без него сервер отвечает `LOGINDISABLED`.
+- **Возможности:** IMAP4rev1, LITERAL+, IDLE (новые письма приходят сами, проверка раз в 5 с), UIDPLUS, MOVE, UNSELECT, NAMESPACE, SPECIAL-USE (Отправленные, Черновики, Корзина, Спам клиент находит сам), ID.
+- **UID** выдаёт база (триггер): письмо, перенесённое в папку из веба или по IMAP, получает новый, больший UID — клиент его не пропустит. Флаги `\Seen`, `\Flagged`, `\Answered`, `\Deleted`; `\Draft` — у писем в «Черновиках».
+- **Письмо целиком** (`BODY[]`) — ровно в том виде, в каком оно пришло по SMTP или через `APPEND`. Для писем, написанных в веб-почте, MIME собирается один раз и сохраняется: размер и байты не меняются между запросами.
+- Каждая команда выполняется на рабочем потоке, не на сетевом. Команды, присланные открытым текстом вместе со `STARTTLS`, не выполняются — соединение закрывается.
+- Папки — плоские (без вложенных), имена — modified UTF-7, кириллица работает.
+
+## Веб-почта
+
+Angular 22 в стиле [synthwave-шаблона](frontend/src/assets/synthwave-design-showcase.html): стеклянные панели, неон, движущаяся сетка (выключается в настройках и при `prefers-reduced-motion`), четыре палитры и высокий контраст. Все таблицы — грид [`@jambotron/aria-grid`](https://gitea.jambotron.com/jambotron_gang/jambotron-aria-grid) (сортировка, страницы, выбор строк, массовые действия), пакет — из реестра npm Gitea (`frontend/.npmrc`).
+
+- **Вход и регистрация.** Регистрация (если открыта, `MAIL_REGISTRATION`) — имя ящика в одном из `MAIL_DOMAINS`, после неё вход сразу. Служебные имена (`postmaster`, `abuse`, `admin`…) заняты. Пароль — от 8 символов.
+- **Папки.** Входящие, Черновики, Отправленные, Спам, Корзина и свои (создать, переименовать, удалить — письма уходят в Корзину). Счётчики непрочитанных обновляются раз в 30 с.
+- **Список писем.** Поиск по теме, отправителю, получателям и тексту; флажок; прочитано/не прочитано; перенос в папку, в Спам и обратно; удаление (в Корзину, из Корзины — насовсем); очистка Корзины и Спама.
+- **Письмо.** HTML-письма — в изолированном `iframe` без скриптов, внешние картинки — только по кнопке (отправитель не узнаёт, что письмо открыли). Вложения скачиваются. Заблокировать отправителя — его письма сразу идут в Спам.
+- **Написать.** Несколько адресов в «Кому» и «Копия», подсказки из контактов, ответ, ответ всем, пересылка. Черновик сохраняется сам каждые 15 с; файлы (до 10 МБ) прикрепляются к черновику и уходят вместе с письмом.
+- **Контакты, заблокированные отправители, настройки** (имя, пароль, место, оформление).
+
+API: `GET /api/config` (без входа), `/api/me`, `/api/me/password`, `/api/folders`, `/api/messages` (`PATCH` — `read`/`flagged`/`folderId`), `/api/drafts`, `/api/send` (`draftId` — с вложениями черновика), `/api/contacts`, `/api/spam/blacklist`.
+
+## Настройки (переменные окружения)
+
+Секреты без значений по умолчанию — без них сервер не стартует. Их можно передать переменными или файлами в `MAILSERVER_SECRETS_DIR` (имя файла = имя переменной).
+
+| Переменная | Что | По умолчанию |
+|---|---|---|
+| `DB_PASSWORD` | пароль PostgreSQL | **обязательно** |
+| `JWT_SECRET` | ключ токенов входа, ≥ 32 байт | **обязательно** |
+| `DB_HOST`, `DB_PORT`, `DB_NAME`, `DB_USER` | база | `localhost`, `5432`, `mailserver`, `mail` |
+| `MAIL_DOMAINS` | наши домены, через запятую | `localhost` |
+| `MAIL_HOSTNAME` | имя сервера в SMTP | `localhost` |
+| `MAIL_ADMIN_EMAIL`, `MAIL_ADMIN_PASSWORD` | первый ящик на пустой базе; без пароля — случайный (в `MAIL_PASSWORDS_FILE` или один раз в логе) | `admin@<первый домен>` |
+| `MAIL_ADMINS` | кто управляет ящиками (Настройки → Mailboxes: создать, новый пароль, выключить), через запятую | первый ящик (`MAIL_ADMIN_EMAIL` или `admin@<первый домен>`) |
+| `HTTPS_PORT` | веб-клиент и API по HTTPS тем же сертификатом, что SMTP/IMAP (в `docker-compose.public.yml` — 8443 → 443: `https://mail.<домен>`); 0 — только HTTP на `server.port` | 0 |
+| `MAIL_PASSWORDS_FILE` | файл (права 600), куда дописываются случайные пароли созданных ящиков: первого и ловушки | — (в образе `/app/data/initial-passwords.txt`) |
+| `MAIL_REGISTRATION` | открыть регистрацию | `false` |
+| `MAIL_CATCH_ALL` | ящик-ловушка: письма на адреса без своего ящика здесь (и на чужие домены) — сюда, наружу ничего; ящик создаётся при старте | — |
+| `SMTP_PORT` | порт SMTP | `3025` |
+| `MAIL_TLS` | TLS для SMTP: `STARTTLS` и порт `SMTPS_PORT` | `true` |
+| `MAIL_TLS_CERT`, `MAIL_TLS_KEY` | свой сертификат: PEM-цепочка и ключ (PKCS#8, `RSA PRIVATE KEY` или `EC PRIVATE KEY`); перечитывается при изменении; без них — самоподписанный | — |
+| `MAIL_TLS_DIR` | где лежит самоподписанный сертификат | `./tls` (в образе `/app/data/tls`) |
+| `SMTPS_PORT` | порт неявного TLS (465); `0` — выключен | `0` |
+| `IMAP_ENABLED`, `IMAP_PORT`, `IMAPS_PORT` | IMAP: включён; порт со STARTTLS; порт неявного TLS (`0` — выключен) | `true`, `3143`, `0` |
+| `IMAP_AUTH_WITHOUT_TLS` | вход в IMAP без TLS — **только** в закрытой сети | `false` |
+| `SMTP_AUTH_WITHOUT_TLS` | разрешить `AUTH` без шифрования — **только** в закрытой сети (docker, ВМ) | `false` |
+| `OUTBOUND_MODE` | `off` / `mx` / `smarthost` | `off` |
+| `OUTBOUND_HOST`, `OUTBOUND_PORT`, `OUTBOUND_USERNAME`, `OUTBOUND_PASSWORD`, `OUTBOUND_TLS` | smarthost (`starttls` / `ssl` / `none`) | —, `587`, —, —, `starttls` |
+| `DKIM_DOMAIN`, `DKIM_SELECTOR`, `DKIM_KEYS_DIR` | DKIM | `localhost`, `mail`, `./dkim-keys` |
+| `SPF_ENABLED`, `DMARC_ENABLED` | проверки входящих | `true` |
+| `MAIL_CORS_ORIGINS` | другие источники для веб-клиента (только разработка) | — |
+| `LOGIN_GUARD` | защита от перебора паролей (см. ниже) | `true` |
+| `LOGIN_GUARD_MAX_PER_IP`, `LOGIN_GUARD_MAX_PER_ACCOUNT` | неверных паролей за окно до блокировки: с одного IP; на один ящик с любых IP | `10`, `20` |
+| `LOGIN_GUARD_WINDOW`, `LOGIN_GUARD_BLOCK`, `LOGIN_GUARD_MAX_BLOCK` | окно подсчёта; первая блокировка; потолок (каждая следующая блокировка того же IP вдвое дольше) | `15m`, `15m`, `24h` |
+| `LOGIN_GUARD_TRUSTED_IPS` | IP через запятую, которые не блокируются по IP (ящик всё равно считается) | — |
+
+### Защита от перебора паролей
+
+Один счётчик на всё, где проверяется пароль: `AUTH` в SMTP (25/587/465), `LOGIN`/`AUTHENTICATE` в IMAP, вход в веб-почту, смена пароля.
+
+- **По IP:** 10 неверных паролей за 15 минут → IP заблокирован на 15 минут, следующая блокировка — 30 минут, потом час… до суток. Сутки тишины — счёт сначала.
+- **По ящику:** 20 неверных паролей на один ящик с разных IP (распределённый перебор) → ящик закрыт на 15 минут, **кроме** IP, с которых в него уже входили успешно (30 дней) — так перебором нельзя запереть владельца из его же почтовой программы.
+- Пока блокировка — пароль **не проверяется** вовсе: SMTP `421 4.7.0` и обрыв, IMAP `* BYE` + `NO [UNAVAILABLE]`, веб `429` с `Retry-After`. Неверный пароль отвечается через секунду; после 3 неверных в одном соединении SMTP и IMAP его закрывают.
+- «Нет такого ящика» и «неверный пароль» снаружи не отличить, оба считаются.
+- В логе: `login guard: IP … blocked for 15 min after 10 failed logins (block #1)`.
+- `X-Forwarded-For` веб-входа принимается только от прокси в частной сети (Caddy Jambotron приходит через docker/WireGuard); с публичного адреса заголовок отбрасывается — подменой IP лимит не обойти.
+- Счётчики в памяти: перезапуск их сбрасывает.
+
+## Разработка
 
 ```bash
-cd mail-server
+docker compose up -d                                               # PostgreSQL на 127.0.0.1:5433
-docker compose up --build
+./gradlew :backend:bootRun --args='--spring.profiles.active=dev'   # API :8080, SMTP :3025, admin@mailserver.local / admin123
+cd frontend && npm install && npx ng serve                         # http://localhost:4200, /api → :8080
+./gradlew :backend:test                                            # тесты (база не нужна)
 ```
 
-Сервисы:
+Профиль `dev` — только для своего компьютера: известные пароли, открытая регистрация, `POST /api/simulate/receive` (письмо в ящик без SMTP).
-- **REST API**: http://localhost:8080
-- **SMTP (приём)**: localhost:3025
-- **IMAP (доступ к письмам)**: localhost:143
-- **Mailpit UI**: http://localhost:8025 (SMTP на порту 1025)
-- **PostgreSQL**: localhost:5432
 
-### 2. Локально
+## Деплой на Jambotron (тест)
 
-Требования:
+В мастере деплоя выбрать `docker-compose.jambotron.yml`, домен дать сервису `mail`, порт `8080`.
-- Java 21
+
-- PostgreSQL 17
+- Пароль базы и ключ токенов создаёт контейнер `secrets-init` при первом запуске (том `secrets`) — вводить ничего не нужно, в git ничего нет.
+- Ящики `admin@mail.test` (первый) и `trap@mail.test` (ловушка) создаются при старте, их пароли печатаются в лог сервиса `mail` при первом запуске (в Jambotron: проект → Сервисы → `mail` → Логи) и лежат в файле `/app/data/initial-passwords.txt` контейнера `mail` (том `data`, права 600): `docker exec <контейнер mail> cat /app/data/initial-passwords.txt`. Прочитать и сменить пароль в настройках.
+- Регистрация открыта (`MAIL_REGISTRATION=true`): любой может завести ящик в `MAIL_DOMAINS`. Наружу письма не уходят, поэтому для тестового стенда это безопасно; закрыть — `MAIL_REGISTRATION=false`.
+- Наружу открыты только веб-почта и API. SMTP (3025) — внутри сети ВМ, наружу ничего не отправляется (`OUTBOUND_MODE=off`).
+- Домен ящиков — `MAIL_DOMAINS` (по умолчанию `mail.test`).
+
+### Ловушка почты для dev и staging (75.4)
+
+В `docker-compose.jambotron.yml` включена ловушка: `MAIL_CATCH_ALL=trap@mail.test`. Письмо на любой адрес, у которого здесь нет своего ящика, — `user@gmail.com`, `nobody@mail.test` — ложится в ящик `trap@mail.test`; письма между ящиками стенда идут как обычно. Наружу не уходит ничего (`OUTBOUND_MODE=off`), порт 25 и репутация IP не нужны. Выключить — `MAIL_CATCH_ALL=` (пусто).
+
+Чтобы staging Jambotron слал письма сюда вместо Resend, его `spring.mail` смотрит на SMTP этого сервера: хост — адрес, по которому staging видит SMTP 3025, без логина и без TLS. Как: в Jambotron, карточка «Домены» проекта → «Внутренние TCP-порты» → сервис `mail`, порт `3025` (Jambotron PR #781). Адрес `vmIp:vmPort` доступен только в сети WireGuard Jambotron, из интернета — нет.
+
+Образ собирается из `backend/Dockerfile` в три этапа: Angular → Spring Boot (веб-клиент внутри jar) → JRE не от root.
+
+### Готовый Docker-образ
+
+Как у htop-web: Drone (`.drone.yml`) собирает `backend/Dockerfile`. На PR образ только собирается, на `master` уходит в реестр Gitea:
+
+```
+gitea.jambotron.com/jambotron_gang/reactive-mail-server:latest
+gitea.jambotron.com/jambotron_gang/reactive-mail-server:<первые 8 символов коммита master>
+```
+
+Реестр публичный: `docker pull` без логина.
+
+`docker-compose.image.yml` — тот же стенд, что `docker-compose.jambotron.yml`, но сервис `mail` берётся из образа, на ВМ ничего не собирается (деплой быстрее, Node и Gradle на ВМ не нужны). В мастере деплоя Jambotron выбрать этот файл; домен — сервису `mail`, порт `8080`. По умолчанию `latest`, он скачивается заново при каждом деплое (`pull_policy: always`); закрепить сборку — переменная `MAIL_IMAGE_TAG=<8 символов коммита>`.
 
 ```bash
-# Запустите PostgreSQL
+docker compose -f docker-compose.image.yml up -d
-docker run -d --name mail-db -p 5432:5432 \
-  -e POSTGRES_DB=mailserver \
-  -e POSTGRES_USER=mail \
-  -e POSTGRES_PASSWORD=secret \
-  postgres:17
-
-# Запустите Mailpit для тестовой отправки
-docker run -d --name mailpit -p 1025:1025 -p 8025:8025 axllent/mailpit
-
-# Соберите и запустите бэкенд
-cd backend
-./gradlew bootRun
 ```
 
-## API
+### Настоящая почта в интернете (75.6)
 
-### Тестовый пользователь
+`docker-compose.public.yml` — приём писем для `MAIL_DOMAINS` и отправка наружу прямо на MX получателей (`OUTBOUND_MODE=mx`, порт 25), с подписью DKIM; регистрация закрыта, ловушки нет. Нужна своя ВМ с публичным адресом (Jambotron 60.8: «Публичный адрес», SMTP «да» — порт 25 по умолчанию закрыт). На этом адресе открыты:
 
-При первом запуске приложения автоматически создаётся тестовый пользователь:
+| Порт | Что |
-
-- **Email:** `admin@mailserver.local`
-- **Пароль:** `admin123`
-
-### Регистрация
-
-```bash
-curl -X POST http://localhost:8080/api/register \
-  -H "Content-Type: application/json" \
-  -d '{"email":"test@example.com","password":"secret123","displayName":"Test User"}'
-```
-
-### Логин
-
-```bash
-curl -X POST http://localhost:8080/api/login \
-  -H "Content-Type: application/json" \
-  -d '{"email":"test@example.com","password":"secret123"}'
-```
-
-Ответ:
-
-```json
-{
-  "token": "eyJhbGci...",
-  "email": "test@example.com"
-}
-```
-
-Все защищённые эндпоинты требуют заголовок `Authorization: Bearer <token>`.
-
-### Получить папки
-
-```bash
-curl http://localhost:8080/api/folders \
-  -H "Authorization: Bearer <token>"
-```
-
-### Получить письма из папки
-
-```bash
-curl "http://localhost:8080/api/messages?folderId=1&page=0&size=20" \
-  -H "Authorization: Bearer <token>"
-```
-
-### Отправить письмо
-
-```bash
-curl -X POST http://localhost:8080/api/send \
-  -H "Content-Type: application/json" \
-  -H "Authorization: Bearer <token>" \
-  -d '{"to":"recipient@example.com","subject":"Hello","body":"Test message"}'
-```
-
-### Симулировать входящее письмо (для тестов)
-
-```bash
-curl -X POST http://localhost:8080/api/simulate/receive \
-  -H "Content-Type: application/json" \
-  -d '{
-    "senderEmail":"sender@example.com",
-    "senderName":"Sender",
-    "recipientEmail":"test@example.com",
-    "subject":"Incoming test",
-    "body":"This is a test message"
-  }'
-```
-
-### Отметить как прочитанное
-
-```bash
-curl -X PUT http://localhost:8080/api/messages/1/read \
-  -H "Authorization: Bearer <token>"
-```
-
-### Удалить письмо
-
-```bash
-curl -X DELETE http://localhost:8080/api/messages/1 \
-  -H "Authorization: Bearer <token>"
-```
-
-### Загрузить вложение к письму
-
-```bash
-curl -X POST http://localhost:8080/api/messages/1/attachments \
-  -H "Authorization: Bearer <token>" \
-  -F "file=@/path/to/file.pdf"
-```
-
-### Получить список вложений письма
-
-```bash
-curl http://localhost:8080/api/messages/1/attachments \
-  -H "Authorization: Bearer <token>"
-```
-
-### Скачать вложение
-
-```bash
-curl http://localhost:8080/api/attachments/1/download \
-  -H "Authorization: Bearer <token>" \
-  -o file.pdf
-```
-
-### Удалить вложение
-
-```bash
-curl -X DELETE http://localhost:8080/api/attachments/1 \
-  -H "Authorization: Bearer <token>"
-```
-
-### Поиск по письмам
-
-Поиск поддерживает два режима: простой поиск по ключевому слову и расширенный поиск с отдельными фильтрами.
-
-**Простой поиск** — ищет по ключевому слову в теме, теле, отправителе и получателе:
-
-```bash
-curl "http://localhost:8080/api/messages/search?folderId=1&keyword=hello" \
-  -H "Authorization: Bearer <token>"
-```
-
-**Расширенный поиск** — используйте отдельные параметры для точной фильтрации:
-
-```bash
-# Поиск по теме
-curl "http://localhost:8080/api/messages/search?folderId=1&subject=report" \
-  -H "Authorization: Bearer <token>"
-
-# Поиск по тексту письма
-curl "http://localhost:8080/api/messages/search?folderId=1&body=invoice" \
-  -H "Authorization: Bearer <token>"
-
-# Поиск по отправителю
-curl "http://localhost:8080/api/messages/search?folderId=1&sender=company.com" \
-  -H "Authorization: Bearer <token>"
-
-# Комбинированный поиск (все фильтры применяются одновременно)
-curl "http://localhost:8080/api/messages/search?folderId=1&subject=report&sender=company.com" \
-  -H "Authorization: Bearer <token>"
-```
-
-Все параметры поиска (`keyword`, `subject`, `body`, `sender`, `recipient`) необязательны. Если ни один параметр не указан, возвращаются все письма папки.
-
-### Отправить письмо через SMTP-сервер
-
-Встроенный SMTP-сервер слушает порт **3025**. Любое письмо, отправленное на этот порт, будет сохранено в базе данных, если получатель зарегистрирован в системе.
-
-```bash
-# Отправить письмо через telnet
-telnet localhost 3025
-```
-
-Или с помощью curl:
-
-```bash
-curl --url 'smtp://localhost:3025' \
-  --mail-from 'sender@example.com' \
-  --mail-rcpt 'test@example.com' \
-  -T <(echo -e 'From: sender@example.com\nTo: test@example.com\nSubject: SMTP Test\n\nHello from SMTP!')
-```
-
-Письмо появится во входящих (INBOX) пользователя `test@example.com`.
-
-### Управление чёрным списком
-
-Добавьте отправителя в чёрный список — письма от него будут автоматически помечаться как спам.
-
-**Получить список заблокированных отправителей:**
-
-```bash
-curl http://localhost:8080/api/spam/blacklist \
-  -H "Authorization: Bearer <token>"
-```
-
-**Добавить отправителя в чёрный список:**
-
-```bash
-curl -X POST http://localhost:8080/api/spam/blacklist \
-  -H "Content-Type: application/json" \
-  -H "Authorization: Bearer <token>" \
-  -d '{"senderEmail":"spammer@example.com","reason":"Спам"}'
-```
-
-**Удалить отправителя из чёрного списка:**
-
-```bash
-curl -X DELETE "http://localhost:8080/api/spam/blacklist?senderEmail=spammer@example.com" \
-  -H "Authorization: Bearer <token>"
-```
-
-Письма от заблокированных отправителей автоматически получают флаг `spam: true` и могут быть отфильтрованы на стороне клиента.
-
-### Подключение через IMAP-сервер
-
-Встроенный IMAP-сервер слушает порт **143**. Вы можете подключиться к нему из любого почтового клиента (Thunderbird, Outlook, Apple Mail) или через telnet для тестирования.
-
-```bash
-# Подключение через telnet
-telnet localhost 143
-```
-
-Пример сессии IMAP:
-
-```
-a LOGIN test@example.com secret123
-a OK LOGIN completed
-
-a LIST "" "*"
-* LIST (\HasNoChildren) "." "INBOX"
-* LIST (\HasNoChildren) "." "Sent"
-a OK LIST completed
-
-a SELECT "INBOX"
-* 5 EXISTS
-* 0 RECENT
-* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
-a OK [READ-WRITE] SELECT completed
-
-a FETCH 1 (BODY[])
-* 1 FETCH (UID 1 FLAGS (\Seen) BODY[] {123
-Hello, this is a test message.
-))
-a OK FETCH completed
-
-a SEARCH ALL
-* SEARCH 1 2 3 4 5
-a OK SEARCH completed
-
-a LOGOUT
-* BYE IMAP4rev1 server terminating
-a OK LOGOUT completed
-```
-
-Поддерживаемые IMAP-команды:
-- **LOGIN** — аутентификация по email и паролю
-- **SELECT / EXAMINE** — выбор папки для работы
-- **FETCH** — получение заголовков и тела писем
-- **SEARCH** — поиск по письмам
-- **STORE** — изменение флагов (прочитано, помечено, удалено)
-- **EXPUNGE** — удаление помеченных писем
-- **LIST / LSUB** — список папок
-- **STATUS** — информация о папке (количество писем, непрочитанных)
-- **CAPABILITY** — список поддерживаемых возможностей
-- **LOGOUT** — выход из сессии
-
-Порт IMAP настраивается через `mailserver.imap.port` в `application.properties` (по умолчанию 143).
-
-### DKIM / SPF / DMARC — защита от подделки писем
-
-Почтовый сервер поддерживает три стандарта защиты электронной почты:
-
-**DKIM (DomainKeys Identified Mail)** — криптографическая подпись писем.
-- При отправке письма автоматически подписываются RSA-ключом (2048 бит)
-- При получении входящих писем проверяется DKIM-подпись отправителя
-- Ключи хранятся в директории `./dkim-keys/` (генерируются автоматически при первом запуске)
-- Публичный ключ публикуется в DNS TXT-записи: `_default._domainkey.<domain>`
-
-**SPF (Sender Policy Framework)** — проверка разрешённых серверов отправителя.
-- При получении письма проверяется SPF DNS-запись домена отправителя
-- Поддерживаемые механизмы: `all`, `ip4`, `ip6`, `mx`, `a`, `include`
-- Локальные адреса (127.0.0.1, 192.168.x.x) пропускаются без проверки
-
-**DMARC (Domain-based Message Authentication, Reporting & Conformance)** — политика обработки.
-- Объединяет результаты SPF и DKIM с проверкой alignment (совпадение доменов)
-- Поддерживаемые политики: `none` (мониторинг), `quarantine` (спам), `reject` (отклонить)
-- Если SPF и DKIM не пройдены, применяется политика DMARC из DNS
-
-**Результат проверки:**
-- Письма, не прошедшие SPF/DKIM/DMARC, автоматически помечаются флагом `spam: true`
-- Логируются результаты всех трёх проверок для каждого входящего письма
-
-**Настройки в `application.properties`:**
-```
-mailserver.dkim.enabled=true
-mailserver.dkim.domain=localhost
-mailserver.dkim.keys-dir=./dkim-keys
-mailserver.spf.enabled=true
-mailserver.spf.local-bypass=true
-mailserver.dmarc.enabled=true
-mailserver.dmarc.local-bypass=true
-```
-
-**Публикация DKIM-ключа в DNS:**
-При первом запуске сервер выводит в лог публичный ключ DKIM. Добавьте его как TXT-запись:
-```
-_name: _default._domainkey.yourdomain.com
-type: TXT
-value: v=DKIM1; k=rsa; p=MIIBojANBgkqhkiG9w0BAQ...
-```
-
-## Модели данных
-
-| Сущность | Описание |
 |---|---|
-| **User** | Почтовый ящик, пароль, квота |
+| 25 | SMTP: письма от других серверов (STARTTLS) |
-| **Folder** | INBOX, Sent, Drafts, Trash, Spam |
+| 587 | submission для почтовых программ (STARTTLS + вход) — тот же SMTP, что 25 |
-| **Message** | Заголовки, тело, флаги (read, flagged, spam) |
+| 465 | SMTPS, неявный TLS |
-| **BlacklistEntry** | Заблокированный отправитель, привязка к пользователю |
+| 993 | IMAPS, неявный TLS |
-| **Attachment** | Имя, MIME-тип, размер, путь к файлу |
+| 80 | только Let's Encrypt (HTTP-01), сервис `acme` |
-| **Contact** | Имя, email, телефон, компания |
 
-## Деплой на VPS
+Сертификат для `MAIL_HOSTNAME` выпускает и продлевает сервис `acme` (lego, ключ EC256, продление за 30 дней, проверка дважды в сутки); хук кладёт пару в том `tls`, сервер перечитывает её сам. `mail` стартует после первого сертификата. Веб-почта (сервис `mail`, порт `8080`) — через Caddy Jambotron под **другим** именем, например `webmail.<домен>`: `MAIL_HOSTNAME` смотрит на публичный адрес ВМ, а не на Caddy.
 
-### Caddy Docker Proxy
+Переменные: `MAIL_DOMAINS` (например `jambocheck.com`), `MAIL_HOSTNAME` (`mail.jambocheck.com`), `ACME_EMAIL` (по умолчанию `postmaster@<домен>`).
 
-Проект использует **Caddy Docker Proxy** для автоматического HTTPS и reverse proxy. Caddy сам генерирует конфиг из `labels` в `docker-compose.prod.yml` — отдельный Caddyfile не нужен.
+DNS до первого запуска:
 
-**Как это работает:**
+| Запись | Значение |
-- Контейнер `mail-server` имеет `labels` с настройками Caddy
+|---|---|
-- `lucaslorentz/caddy-docker-proxy` следит за Docker через socket и автоматически создаёт виртуальные хосты
+| `A mail.<домен>` | публичный адрес ВМ |
-- HTTPS-сертификат от Let's Encrypt получается автоматически
+| PTR публичного адреса | `mail.<домен>` (панель хостера, Reverse DNS) |
+| `MX <домен>` | `10 mail.<домен>` |
+| `TXT <домен>` | `v=spf1 ip4:<публичный адрес> -all` |
+| `TXT _dmarc.<домен>` | `v=DMARC1; p=none; rua=mailto:postmaster@<домен>` |
+| `TXT mail._domainkey.<домен>` | из лога `mail` при первом запуске (ключ DKIM лежит в томе `data`) |
 
-**Ключевые labels:**
+Ящик `admin@<домен>` — пароль в логе `mail` при первом запуске и в `/app/data/initial-passwords.txt`.
 
-| Label | Описание |
+## Не сделано
-|-------|----------|
-| `caddy: mail.jambotron.com` | Домен, на котором доступен сервис |
-| `caddy.route.api.reverse_proxy` | Проксирует `/api/*` на Spring Boot (порт 8080) |
-| `caddy.route.static.root` | Корневая директория для Angular фронтенда |
-| `caddy.route.static.file_server` | Раздаёт статические файлы Angular |
 
-**Запуск на VPS:**
+- [ ] IMAP: проверить с Thunderbird на настоящем адресе; вложенные папки, CONDSTORE/QRESYNC, поиск по `BODY`/`TEXT` без перебора писем.
-
+- [ ] Пересылка не берёт вложения исходного письма — их надо прикрепить заново.
-```bash
+- [ ] Встроенные картинки HTML-писем (`cid:`) показываются как вложения, а не внутри письма.
-# Клонируйте репозиторий
+- [x] Защита входа от перебора: SMTP, IMAP, веб (лимит по IP и по ящику, см. «Защита от перебора паролей»).
-git clone https://gitea.jambotron.com/jambotron_gang/reactive-mail-server.git
+- [ ] Защита регистрации от массового заведения ящиков (лимит, капча) — пока регистрация на публичной почте закрыта.
-cd reactive-mail-server
+- [ ] Письмо нескольким получателям: при ошибке на втором первый может получить его дважды (после повтора отправителя).
-
+- [ ] Настоящая почта (75.6): `docker-compose.public.yml` готов, первый запуск — `mail.jambocheck.com` на публичном адресе Horizon; адрес «прогревать» несколько недель, письма пользователям Jambotron пока через Resend (75.5).
-# Соберите фронтенд
-cd frontend && npm install && npx ng build --configuration=production
-cd ..
-
-# Запустите
-docker compose -f docker-compose.prod.yml up -d --build
-```
-
-**Перед запуском:**
-1. Замените `mail.jambotron.com` на ваш домен в `docker-compose.prod.yml`
-2. Настройте PTR (Reverse DNS) у хостера — IP → `mail.jambotron.com`
-3. Добавьте DNS-записи: A (`mail` → IP), MX (`@` → `mail.jambotron.com`), TXT (`v=spf1 ip4:<IP> -all`)
-4. Откройте порты: 80, 443, 25 (SMTP relay), 3025 (SMTP приём)
-
-## TODO
-
-- [x] Хэширование паролей (BCrypt)
-- [x] Аутентификация (JWT)
-- [x] Приём SMTP (встроенный сервер на WebFlux TcpServer)
-- [x] IMAP-сервер (встроенный, порт 143)
-- [x] Вложения (загрузка/скачивание)
-- [x] Поиск по письмам (по теме, телу, отправителю, получателю)
-- [x] Angular фронтенд (v22 + Tailwind CSS + Synthwave дизайн)
-- [x] Антиспам (чёрный список отправителей)
-- [x] DKIM/SPF/DMARC (подпись, верификация, DNS-проверка)
-- [x] SMTP релей (доставка на внешнюю почту)
-- [x] Контакты (адресная книга)
-- [x] Reply / Forward
-- [x] Пагинация писем
-- [x] HTML/Markdown режим
-- [x] Caddy Docker Proxy (автоматический HTTPS)
-- [ ] TLS шифрование SMTP/IMAP
 
 ## Лицензия
 

backend/Dockerfile

@@ -1,17 +1,35 @@
-# Stage 1: Build
+# Build context: repository root (docker compose: context ".", dockerfile backend/Dockerfile)
-FROM eclipse-temurin:21-jdk-alpine AS build
+# No Alpine images: on Jambotron staging VMs (kernel 6.18.55-virt) binaries from Alpine 3.24.3
-WORKDIR /app
+# (musl 1.2.6) die with "Bus error" — java survived, curl in the healthcheck did not (2026-11-05)
-COPY backend/build.gradle ./
-COPY gradlew ./
-COPY gradle gradle
-COPY backend/src src
-RUN chmod +x gradlew
-RUN ./gradlew bootJar --no-daemon
 
-# Stage 2: Run
+# 1. Web client (Angular) — served by the backend from classpath:/static
-FROM eclipse-temurin:21-jre-alpine
+FROM node:22-bookworm-slim AS web
+WORKDIR /web
+COPY frontend/package*.json frontend/.npmrc ./
+RUN npm install --no-audit --no-fund
+COPY frontend/ ./
+RUN npx ng build --configuration=production
+
+# 2. Backend
+FROM eclipse-temurin:21-jdk AS build
 WORKDIR /app
-COPY --from=build /app/build/libs/*.jar app.jar
+COPY gradlew settings.gradle ./
-RUN mkdir -p /app/attachments /app/dkim-keys
+COPY gradle gradle
+COPY backend/build.gradle backend/
+COPY backend/src backend/src
+COPY --from=web /web/dist/frontend/browser backend/src/main/resources/static
+RUN chmod +x gradlew && ./gradlew :backend:bootJar --no-daemon -x test
+
+# 3. Runtime: not root; data in /app/data (volume)
+FROM eclipse-temurin:21-jre
+# Ubuntu image, curl included; own user: "mail" already exists (uid 8)
+RUN groupadd -r -g 10001 app && useradd -r -u 10001 -g app -d /app -s /usr/sbin/nologin app \
+    && mkdir -p /app/data/attachments /app/data/dkim-keys /app/data/tls && chown -R app:app /app/data
+WORKDIR /app
+COPY --from=build /app/backend/build/libs/*.jar app.jar
+USER app
+ENV MAIL_ATTACHMENTS_DIR=/app/data/attachments DKIM_KEYS_DIR=/app/data/dkim-keys MAIL_PASSWORDS_FILE=/app/data/initial-passwords.txt MAIL_TLS_DIR=/app/data/tls
 EXPOSE 8080 3025
-ENTRYPOINT ["java", "-jar", "app.jar"]
+HEALTHCHECK --interval=30s --timeout=5s --start-period=60s --retries=3 \
+    CMD curl -fsS http://localhost:8080/actuator/health || exit 1
+ENTRYPOINT ["java", "-XX:MaxRAMPercentage=75", "-jar", "app.jar"]

backend/build.gradle

@@ -23,6 +23,8 @@ dependencies {
     // R2DBC — реактивный доступ к PostgreSQL (вместо JPA/Hibernate)
     implementation 'org.springframework.boot:spring-boot-starter-data-r2dbc'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
+    // health для проверки контейнера (только /actuator/health)
+    implementation 'org.springframework.boot:spring-boot-starter-actuator'
     // SMTP сервер на Spring — встроенный, без внешних зависимостей
     implementation 'org.eclipse.angus:angus-mail:2.0.3'
     implementation 'org.springframework.boot:spring-boot-starter-security'
@@ -35,6 +37,12 @@ dependencies {
     implementation 'org.bouncycastle:bcpkix-jdk18on:1.78.1'
     implementation 'org.bouncycastle:bcprov-jdk18on:1.78.1'
 
+    // DKIM: подпись исходящих (simple-java-mail) и проверка входящих (Apache James jDKIM)
+    implementation 'org.simplejavamail:utils-mail-dkim:3.4.0'
+    implementation 'org.apache.james.jdkim:apache-jdkim-library:0.5'
+    // DNS: MX-записи для доставки
+    implementation 'dnsjava:dnsjava:3.6.3'
+
     // R2DBC PostgreSQL драйвер
     runtimeOnly 'org.postgresql:r2dbc-postgresql:1.0.4.RELEASE'
 
@@ -43,10 +51,15 @@ dependencies {
     runtimeOnly 'org.postgresql:postgresql'
 
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
-    testImplementation 'com.icegreen:greenmail:2.0.1'
+    testImplementation 'com.icegreen:greenmail:2.1.15'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
+// only the executable jar (the plain jar would make two files in build/libs)
+tasks.named('jar') {
+    enabled = false
+}
+
 tasks.named('test') {
     useJUnitPlatform()
 }

backend/src/main/java/com/mailserver/config/DataInitializer.java

@@ -4,24 +4,91 @@ import com.mailserver.repository.UserRepository;
 import com.mailserver.service.UserService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.CommandLineRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.security.SecureRandom;
+import java.time.Instant;
+import java.util.Base64;
+import java.util.Locale;
+
+/**
+ * Mailboxes the server needs on start:
+ * <ul>
+ *   <li>the first mailbox on an empty database — {@code mailserver.admin.email} (default admin@&lt;first domain&gt;)
+ *       with {@code mailserver.admin.password};</li>
+ *   <li>the catch-all mailbox ({@code mailserver.catch-all}) if it does not exist yet — mail to unknown addresses is
+ *       stored there, so it must exist.</li>
+ * </ul>
+ * A generated password is printed to the log once (visible in Jambotron: project → Services → mail → Logs) and appended
+ * to {@code mailserver.passwords-file} (mode 600, in the data volume) — change it after the first login.
+ */
 @Configuration
 public class DataInitializer {
 
     private static final Logger log = LoggerFactory.getLogger(DataInitializer.class);
 
     @Bean
-    public CommandLineRunner initDatabase(UserService userService, UserRepository userRepository) {
+    public CommandLineRunner initDatabase(UserService userService, UserRepository userRepository, MailDomains domains,
+                                          @Value("${mailserver.admin.email:}") String email,
+                                          @Value("${mailserver.admin.password:}") String password,
+                                          @Value("${mailserver.passwords-file:}") String passwordsFile) {
         return args -> {
-            userRepository.count().block(); // Ждём инициализации
+            Path file = passwordsFile.isBlank() ? null : Path.of(passwordsFile);
             if (userRepository.count().block() == 0) {
-                log.info("База данных пуста, создаю тестового пользователя...");
+                String address = email.isBlank() ? "admin@" + domains.domains().iterator().next() : email.trim().toLowerCase(Locale.ROOT);
-                userService.register("admin@mailserver.local", "admin123", "Администратор").block();
+                create(userService, address, password, "Administrator", file);
-                log.info("✓ Тестовый пользователь создан: admin@mailserver.local / admin123");
+            }
+            String catchAll = domains.catchAll();
+            if (catchAll != null && !Boolean.TRUE.equals(userRepository.existsByEmail(catchAll).block())) {
+                create(userService, catchAll, "", "Mail trap", file);
             }
         };
     }
+
+    private static void create(UserService userService, String address, String password, String name, Path file)
+            throws IOException {
+        boolean generated = password.isBlank();
+        String secret = generated ? randomPassword() : password;
+        userService.register(address, secret, name).block();
+        if (!generated) {
+            log.info("Mailbox created: {}", address);
+        } else if (file != null) {
+            appendPassword(file, address, secret);
+            // also in the log: the owner sees it in Jambotron (project → Services → mail → Logs) without a shell
+            log.warn("Mailbox created: {} — password: {} (also in {}; change it)", address, secret, file);
+        } else {
+            log.warn("Mailbox created: {} — password: {} (shown once, change it)", address, secret);
+        }
+    }
+
+    static void appendPassword(Path file, String address, String password) throws IOException {
+        if (file.getParent() != null) {
+            Files.createDirectories(file.getParent());
+        }
+        if (!Files.exists(file)) {
+            Files.createFile(file);
+            try {
+                Files.setPosixFilePermissions(file, PosixFilePermissions.fromString("rw-------"));
+            } catch (UnsupportedOperationException ignored) {
+                // not a POSIX file system (Windows) — nothing to restrict
+            }
+        }
+        Files.writeString(file, Instant.now() + " " + address + " " + password + System.lineSeparator(),
+                StandardCharsets.UTF_8, StandardOpenOption.APPEND);
+    }
+
+    private static String randomPassword() {
+        byte[] bytes = new byte[18];
+        new SecureRandom().nextBytes(bytes);
+        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
+    }
 }

backend/src/main/java/com/mailserver/config/HttpsConfig.java

@@ -0,0 +1,81 @@
+package com.mailserver.config;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.context.SmartLifecycle;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.server.HttpServer;
+
+import java.time.Duration;
+
+/**
+ * The web client and API over HTTPS on the mail host itself (mailserver.https.port, in public compose 8443 →
+ * published 443): https://mail.jambocheck.com opens the web mail, no second name through Jambotron's Caddy.
+ * Same certificate as SMTP/IMAP (Let's Encrypt from the acme service, reloaded when renewed). The plain HTTP port
+ * (8080) stays for a reverse proxy inside the network (staging: domain in Jambotron).
+ */
+@Configuration
+public class HttpsConfig {
+
+    @Bean
+    @ConditionalOnExpression("${mailserver.https.port:0} > 0 and ${mailserver.tls.enabled:true}")
+    public HttpsServer httpsServer(HttpHandler handler, MailServerConfig.SmtpTlsContext tls,
+                                   @Value("${mailserver.smtp.host:0.0.0.0}") String host,
+                                   @Value("${mailserver.https.port}") int port) {
+        return new HttpsServer(handler, tls, host, port);
+    }
+
+    public static class HttpsServer implements SmartLifecycle {
+
+        private static final Logger log = LoggerFactory.getLogger(HttpsServer.class);
+
+        private final HttpHandler handler;
+        private final MailServerConfig.SmtpTlsContext tls;
+        private final String host;
+        private final int port;
+        private volatile DisposableServer server;
+
+        HttpsServer(HttpHandler handler, MailServerConfig.SmtpTlsContext tls, String host, int port) {
+            this.handler = handler;
+            this.tls = tls;
+            this.host = host;
+            this.port = port;
+        }
+
+        @Override
+        public void start() {
+            server = HttpServer.create()
+                    .host(host)
+                    .port(port)
+                    .secure(spec -> spec.sslContext(tls.context()))
+                    // HSTS: Spring Security adds it for HTTPS requests by itself
+                    .handle(new ReactorHttpHandlerAdapter(handler))
+                    .bindNow(Duration.ofSeconds(30));
+            log.info("HTTPS (web client + API) listening on {}:{}", host, server.port());
+        }
+
+        @Override
+        public void stop() {
+            DisposableServer current = server;
+            if (current != null) {
+                current.disposeNow(Duration.ofSeconds(10));
+                server = null;
+            }
+        }
+
+        @Override
+        public boolean isRunning() {
+            return server != null;
+        }
+
+        public int port() {
+            return server == null ? -1 : server.port();
+        }
+    }
+}

backend/src/main/java/com/mailserver/config/ImapConfig.java

@@ -0,0 +1,60 @@
+package com.mailserver.config;
+
+import com.mailserver.security.LoginGuard;
+import com.mailserver.imap.DbImapStore;
+import com.mailserver.imap.ImapServer;
+import com.mailserver.imap.ImapStore;
+import com.mailserver.repository.AttachmentRepository;
+import com.mailserver.repository.MessageRepository;
+import com.mailserver.repository.UserRepository;
+import com.mailserver.service.MailService;
+import com.mailserver.service.MessageSources;
+import com.mailserver.service.UserService;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.r2dbc.core.DatabaseClient;
+import org.springframework.util.unit.DataSize;
+
+import java.time.Duration;
+
+/** IMAP (75.2): STARTTLS on mailserver.imap.port, implicit TLS on mailserver.imaps.port when set. */
+@Configuration
+public class ImapConfig {
+
+    @Bean
+    public ImapStore imapStore(DatabaseClient db, UserRepository users, UserService userService, MailService mailService,
+                               MessageRepository messages, AttachmentRepository attachments, MessageSources sources,
+                               @Value("${mailserver.smtp.hostname:localhost}") String hostname) {
+        return new DbImapStore(db, users, userService, mailService, messages, attachments, sources, hostname);
+    }
+
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    @ConditionalOnProperty(name = "mailserver.imap.enabled", havingValue = "true", matchIfMissing = true)
+    public ImapServer imapServer(ImapStore store, MailServerConfig.SmtpTlsContext tls, LoginGuard guard,
+                                 @Value("${mailserver.imap.host:0.0.0.0}") String host,
+                                 @Value("${mailserver.imap.port:3143}") int port,
+                                 @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                                 @Value("${mailserver.imap.auth-without-tls:false}") boolean authWithoutTls,
+                                 @Value("${mailserver.imap.max-literal:50MB}") DataSize maxLiteral,
+                                 @Value("${mailserver.imap.idle-timeout:30m}") Duration idleTimeout,
+                                 @Value("${mailserver.imap.idle-poll:5s}") Duration idlePoll) {
+        return new ImapServer(new ImapServer.Settings(host, port, hostname, authWithoutTls, tls.context(), false,
+                (int) maxLiteral.toBytes(), idleTimeout, idlePoll), store, guard);
+    }
+
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    @ConditionalOnExpression("'${mailserver.imap.enabled:true}' == 'true' and ${mailserver.imaps.port:0} > 0 and ${mailserver.tls.enabled:true}")
+    public ImapServer imapsServer(ImapStore store, MailServerConfig.SmtpTlsContext tls, LoginGuard guard,
+                                  @Value("${mailserver.imap.host:0.0.0.0}") String host,
+                                  @Value("${mailserver.imaps.port}") int port,
+                                  @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                                  @Value("${mailserver.imap.max-literal:50MB}") DataSize maxLiteral,
+                                  @Value("${mailserver.imap.idle-timeout:30m}") Duration idleTimeout,
+                                  @Value("${mailserver.imap.idle-poll:5s}") Duration idlePoll) {
+        return new ImapServer(new ImapServer.Settings(host, port, hostname, false, tls.context(), true,
+                (int) maxLiteral.toBytes(), idleTimeout, idlePoll), store, guard);
+    }
+}

backend/src/main/java/com/mailserver/config/ImapServerConfig.java

@@ -1,580 +0,0 @@
-package com.mailserver.config;
-
-import com.mailserver.repository.FolderRepository;
-import com.mailserver.repository.MessageRepository;
-import com.mailserver.repository.UserRepository;
-import com.mailserver.service.UserService;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.context.annotation.Configuration;
-
-import jakarta.annotation.PostConstruct;
-import jakarta.annotation.PreDestroy;
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.PrintWriter;
-import java.net.ServerSocket;
-import java.net.Socket;
-import java.nio.charset.StandardCharsets;
-import java.time.Instant;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Встроенный IMAP-сервер для почтового сервера.
- * Поддерживает основные команды IMAP4rev1: LOGIN, SELECT, FETCH, SEARCH, STORE, EXPUNGE, LOGOUT.
- * Запускается при старте приложения и останавливается при завершении.
- */
-@Configuration
-public class ImapServerConfig {
-
-    private static final Logger log = LoggerFactory.getLogger(ImapServerConfig.class);
-
-    @Value("${mailserver.imap.enabled:true}")
-    private boolean enabled;
-
-    @Value("${mailserver.imap.port:143}")
-    private int port;
-
-    @Value("${mailserver.imap.hostname:localhost}")
-    private String hostname;
-
-    private final UserRepository userRepository;
-    private final FolderRepository folderRepository;
-    private final MessageRepository messageRepository;
-    private final UserService userService;
-
-    private ServerSocket serverSocket;
-    private ExecutorService executorService;
-
-    public ImapServerConfig(UserRepository userRepository, FolderRepository folderRepository,
-                           MessageRepository messageRepository, UserService userService) {
-        this.userRepository = userRepository;
-        this.folderRepository = folderRepository;
-        this.messageRepository = messageRepository;
-        this.userService = userService;
-    }
-
-    @PostConstruct
-    public void start() {
-        if (!enabled) {
-            log.info("IMAP-сервер отключён (mailserver.imap.enabled=false)");
-            return;
-        }
-
-        executorService = Executors.newCachedThreadPool();
-
-        try {
-            serverSocket = new ServerSocket(port);
-            log.info("IMAP-сервер запущен на порту {} (хост: {})", port, hostname);
-
-            // Принимаем подключения в цикле
-            while (!serverSocket.isClosed()) {
-                try {
-                    Socket clientSocket = serverSocket.accept();
-                    executorService.submit(() -> handleClient(clientSocket));
-                } catch (IOException e) {
-                    if (!serverSocket.isClosed()) {
-                        log.error("Ошибка при принятии подключения", e);
-                    }
-                }
-            }
-        } catch (IOException e) {
-            if (serverSocket == null || !serverSocket.isClosed()) {
-                log.error("Не удалось запустить IMAP-сервер на порту {}", port, e);
-            }
-        }
-    }
-
-    @PreDestroy
-    public void stop() {
-        log.info("Остановка IMAP-сервера...");
-        try {
-            if (serverSocket != null && !serverSocket.isClosed()) {
-                serverSocket.close();
-            }
-        } catch (IOException e) {
-            log.error("Ошибка при остановке IMAP-сервера", e);
-        }
-
-        if (executorService != null) {
-            executorService.shutdown();
-            try {
-                if (!executorService.awaitTermination(5, TimeUnit.SECONDS)) {
-                    executorService.shutdownNow();
-                }
-            } catch (InterruptedException e) {
-                executorService.shutdownNow();
-                Thread.currentThread().interrupt();
-            }
-        }
-        log.info("IMAP-сервер остановлен");
-    }
-
-    private void handleClient(Socket socket) {
-        String clientAddress = socket.getInetAddress().getHostAddress();
-        log.info("Новое IMAP-подключение от {}", clientAddress);
-
-        try (socket;
-             PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
-             BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8))) {
-
-            // Отправляем приветствие
-            out.println("* OK IMAP4rev1 Server Ready");
-
-            String username = null;
-            String line;
-
-            while (username == null && (line = in.readLine()) != null) {
-                String[] parts = parseCommand(line);
-                if (parts == null) continue;
-
-                String tag = parts[0];
-                String command = parts[1].toUpperCase();
-
-                switch (command) {
-                    case "LOGIN" -> {
-                        if (parts.length >= 4) {
-                            String email = parts[2].toLowerCase();
-                            String password = parts[3];
-
-                            // Проверяем пароль через BCrypt
-                            com.mailserver.domain.User user = userRepository.findByEmail(email).block();
-                            if (user != null && userService.checkPassword(user, password)) {
-                                username = email;
-                                out.println(tag + " OK LOGIN completed");
-                                log.info("Пользователь {} успешно авторизован через IMAP", email);
-                            } else {
-                                out.println(tag + " NO LOGIN failed: invalid credentials");
-                                log.warn("Неудачная попытка IMAP-авторизации для пользователя {}", email);
-                            }
-                        } else {
-                            out.println(tag + " BAD Invalid LOGIN command");
-                        }
-                    }
-                    case "CAPABILITY" -> {
-                        out.println("* CAPABILITY IMAP4rev1 UNSELECT IDLE NAMESPACE LITERAL+");
-                        out.println(tag + " OK Capability completed");
-                    }
-                    case "LOGOUT" -> {
-                        out.println("* BYE IMAP4rev1 server terminating");
-                        out.println(tag + " OK LOGOUT completed");
-                        return;
-                    }
-                    default -> {
-                        if (username == null) {
-                            out.println(tag + " BAD Authentication required");
-                        } else {
-                            handleAuthenticatedCommand(tag, command, parts, username, out, in);
-                        }
-                    }
-                }
-            }
-        } catch (IOException e) {
-            log.error("Ошибка при обработке IMAP-подключения от {}", clientAddress, e);
-        } finally {
-            log.info("IMAP-подключение от {} закрыто", clientAddress);
-        }
-    }
-
-    private void handleAuthenticatedCommand(String tag, String command, String[] parts,
-                                           String username, PrintWriter out, BufferedReader in) {
-        switch (command) {
-            case "SELECT" -> handleSelect(tag, parts, username, out);
-            case "EXAMINE" -> handleSelect(tag, parts, username, out); // EXAMINE = SELECT в read-only режиме
-            case "FETCH" -> handleFetch(tag, parts, username, out);
-            case "SEARCH" -> handleSearch(tag, parts, username, out);
-            case "STORE" -> handleStore(tag, parts, username, out);
-            case "EXPUNGE" -> handleExpunge(tag, username, out);
-            case "LIST" -> handleList(tag, username, out);
-            case "LSUB" -> handleList(tag, username, out); // LSUB = LIST для подписок
-            case "STATUS" -> handleStatus(tag, parts, username, out);
-            case "ID" -> {
-                out.println("* ID (\"name\" \"MailServer IMAP\" \"version\" \"1.0\")");
-                out.println(tag + " OK ID completed");
-            }
-            default -> {
-                out.println(tag + " BAD Unknown command: " + command);
-            }
-        }
-    }
-
-    private void handleSelect(String tag, String[] parts, String username, PrintWriter out) {
-        if (parts.length < 3) {
-            out.println(tag + " BAD Invalid SELECT command");
-            return;
-        }
-
-        String folderName = parts[2].replace("\"", "");
-        com.mailserver.domain.User userTemp = userRepository.findByEmail(username).block();
-        if (userTemp == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-        com.mailserver.domain.Folder folder = folderRepository.findByUserIdAndName(
-                userTemp.getId(), folderName).block();
-
-        if (folder == null) {
-            out.println(tag + " NO [NONEXISTENT] Mailbox does not exist");
-            return;
-        }
-
-        long messageCount = messageRepository.findByFolderId(folder.getId(),
-                org.springframework.data.domain.PageRequest.of(0, 1)).count().block();
-
-        out.println("* " + messageCount + " EXISTS");
-        out.println("* 0 RECENT");
-        out.println("* FLAGS (\\Answered \\Flagged \\Deleted \\Seen \\Draft)");
-        out.println(tag + " [OK] [UNSEEN 1] " + (messageCount > 0 ? "There are unseen messages in the mailbox." : "The mailbox has no unseen messages."));
-        out.println(tag + " OK [READ-WRITE] SELECT completed");
-    }
-
-    private void handleFetch(String tag, String[] parts, String username, PrintWriter out) {
-        if (parts.length < 4) {
-            out.println(tag + " BAD Invalid FETCH command");
-            return;
-        }
-
-        String messageId = parts[2];
-        String item = parts[3];
-
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        // Получаем все сообщения пользователя
-        java.util.List<com.mailserver.domain.Folder> folders = folderRepository.findByUserId(user.getId()).collectList().block();
-        java.util.List<com.mailserver.domain.Message> allMessages = new java.util.ArrayList<>();
-        for (com.mailserver.domain.Folder folder : folders) {
-            allMessages.addAll(messageRepository.findByFolderId(folder.getId(),
-                    org.springframework.data.domain.PageRequest.of(0, 1000)).collectList().block());
-        }
-
-        // Находим сообщение по UID или индексу
-        com.mailserver.domain.Message message = null;
-        if (item.contains("UID")) {
-            // UID FETCH
-            try {
-                long uid = Long.parseLong(messageId);
-                for (com.mailserver.domain.Message msg : allMessages) {
-                    if (msg.getId().equals(uid)) {
-                        message = msg;
-                        break;
-                    }
-                }
-            } catch (NumberFormatException e) {
-                out.println(tag + " BAD Invalid UID");
-                return;
-            }
-        } else {
-            // FETCH по индексу (1-based)
-            try {
-                int index = Integer.parseInt(messageId) - 1;
-                if (index >= 0 && index < allMessages.size()) {
-                    message = allMessages.get(index);
-                }
-            } catch (NumberFormatException e) {
-                out.println(tag + " BAD Invalid message set");
-                return;
-            }
-        }
-
-        if (message == null) {
-            out.println(tag + " NO Message not found");
-            return;
-        }
-
-        // Формируем ответ FETCH
-        StringBuilder flags = new StringBuilder();
-        if (message.isRead()) flags.append("\\Seen ");
-        if (message.isFlagged()) flags.append("\\Flagged ");
-        if (message.isSpam()) flags.append("\\Deleted ");
-        if (message.getBody() != null && !message.getBody().isEmpty()) flags.append("\\Answered ");
-
-        out.println("* " + messageId + " FETCH (");
-        out.println("  UID " + message.getId());
-        out.println("  FLAGS (" + flags.toString().trim() + ")");
-        out.println("  INTERNALDATE \"" + formatImapDate(message.getReceivedAt()) + "\"");
-        out.println("  RFC822.SIZE " + (message.getMessageSize() != null ? message.getMessageSize() : 0));
-        out.println("  ENVELOPE (");
-        out.println("    \"" + escapeString(message.getReceivedAt() != null ? message.getReceivedAt().toString() : "") + "\"");
-        out.println("    \"" + escapeString(message.getSubject() != null ? message.getSubject() : "") + "\"");
-        out.println("    (\"" + escapeString(message.getSenderName() != null ? message.getSenderName() : "") + "\" 0 \"\" \"" + escapeString(message.getSenderEmail() != null ? message.getSenderEmail() : "") + "\")");
-        out.println("    (\"" + escapeString(message.getRecipientEmail() != null ? message.getRecipientEmail() : "") + "\")");
-        out.println("    (\"" + escapeString(message.getRecipientEmail() != null ? message.getRecipientEmail() : "") + "\")");
-        out.println("    (\"" + escapeString(message.getSenderEmail() != null ? message.getSenderEmail() : "") + "\")");
-        out.println("    NIL");
-        out.println("    NIL");
-        out.println("    NIL");
-        out.println("  )");
-
-        // Если запрошено тело сообщения
-        if (item.contains("BODY[]") || item.contains("RFC822")) {
-            out.println("  BODY[] {");
-            String body = message.getBody() != null ? message.getBody() : "";
-            out.println(body.length());
-            out.println(body);
-            out.println(")");
-        }
-
-        out.println(")");
-        out.println(tag + " OK FETCH completed");
-    }
-
-    private void handleSearch(String tag, String[] parts, String username, PrintWriter out) {
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        com.mailserver.domain.Folder inbox = folderRepository.findByUserIdAndName(user.getId(), "INBOX").block();
-        if (inbox == null) {
-            out.println(tag + " OK SEARCH completed");
-            return;
-        }
-
-        // Простой поиск по ключевому слову
-        String keyword = null;
-        for (int i = 2; i < parts.length; i++) {
-            if (!parts[i].equals("ALL") && !parts[i].equals("FROM") && !parts[i].equals("SUBJECT") && !parts[i].equals("BODY")) {
-                keyword = parts[i];
-                break;
-            }
-        }
-
-        java.util.List<Long> messageIds;
-        if (keyword != null && !keyword.isEmpty()) {
-            var results = messageRepository.searchInFolder(inbox.getId(), keyword,
-                    org.springframework.data.domain.PageRequest.of(0, 100)).collectList().block();
-            messageIds = results.stream()
-                    .map(com.mailserver.domain.Message::getId)
-                    .collect(java.util.stream.Collectors.toList());
-        } else {
-            var results = messageRepository.findByFolderId(inbox.getId(),
-                    org.springframework.data.domain.PageRequest.of(0, 100)).collectList().block();
-            messageIds = results.stream()
-                    .map(com.mailserver.domain.Message::getId)
-                    .collect(java.util.stream.Collectors.toList());
-        }
-
-        StringBuilder ids = new StringBuilder();
-        for (Long id : messageIds) {
-            ids.append(id).append(" ");
-        }
-
-        out.println("* SEARCH " + ids.toString().trim());
-        out.println(tag + " OK SEARCH completed");
-    }
-
-    private void handleStore(String tag, String[] parts, String username, PrintWriter out) {
-        if (parts.length < 5) {
-            out.println(tag + " BAD Invalid STORE command");
-            return;
-        }
-
-        String messageId = parts[2];
-        String item = parts[3].toUpperCase();
-        String value = parts[4].toUpperCase();
-
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        // Получаем все сообщения пользователя
-        java.util.List<com.mailserver.domain.Folder> folders = folderRepository.findByUserId(user.getId()).collectList().block();
-        java.util.List<com.mailserver.domain.Message> allMessages = new java.util.ArrayList<>();
-        for (com.mailserver.domain.Folder folder : folders) {
-            allMessages.addAll(messageRepository.findByFolderId(folder.getId(),
-                    org.springframework.data.domain.PageRequest.of(0, 1000)).collectList().block());
-        }
-
-        com.mailserver.domain.Message message = null;
-        try {
-            int index = Integer.parseInt(messageId) - 1;
-            if (index >= 0 && index < allMessages.size()) {
-                message = allMessages.get(index);
-            }
-        } catch (NumberFormatException e) {
-            out.println(tag + " BAD Invalid message set");
-            return;
-        }
-
-        if (message == null) {
-            out.println(tag + " NO Message not found");
-            return;
-        }
-
-        boolean saved = false;
-        if (item.contains("+FLAGS") || item.contains("FLAGS")) {
-            if (value.contains("\\SEEN")) {
-                message.setRead(true);
-                saved = true;
-            }
-            if (value.contains("\\FLAGGED")) {
-                message.setFlagged(true);
-                saved = true;
-            }
-            if (value.contains("\\DELETED")) {
-                message.setSpam(true); // Используем spam как флаг удаления для IMAP
-                saved = true;
-            }
-        }
-
-        if (item.contains("-FLAGS")) {
-            if (value.contains("\\SEEN")) {
-                message.setRead(false);
-                saved = true;
-            }
-            if (value.contains("\\FLAGGED")) {
-                message.setFlagged(false);
-                saved = true;
-            }
-        }
-
-        if (saved) {
-            messageRepository.save(message).block();
-        }
-
-        out.println("* " + messageId + " FETCH (FLAGS (" + formatFlags(message) + "))");
-        out.println(tag + " OK STORE completed");
-    }
-
-    private void handleExpunge(String tag, String username, PrintWriter out) {
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        java.util.List<com.mailserver.domain.Folder> folders = folderRepository.findByUserId(user.getId()).collectList().block();
-        for (com.mailserver.domain.Folder folder : folders) {
-            var messages = messageRepository.findByFolderId(folder.getId(),
-                    org.springframework.data.domain.PageRequest.of(0, 1000)).collectList().block();
-            for (com.mailserver.domain.Message message : messages) {
-                if (message.isSpam()) {
-                    messageRepository.delete(message).block();
-                    folder.setMessageCount(Math.max(0, folder.getMessageCount() - 1));
-                    folderRepository.save(folder).block();
-                }
-            }
-        }
-
-        out.println("* 0 EXPUNGE");
-        out.println(tag + " OK EXPUNGE completed");
-    }
-
-    private void handleList(String tag, String username, PrintWriter out) {
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        java.util.List<com.mailserver.domain.Folder> folders = folderRepository.findByUserId(user.getId()).collectList().block();
-        for (com.mailserver.domain.Folder folder : folders) {
-            out.println("* LIST (\\HasNoChildren) \".\" \"" + folder.getName() + "\"");
-        }
-
-        out.println(tag + " OK LIST completed");
-    }
-
-    private void handleStatus(String tag, String[] parts, String username, PrintWriter out) {
-        if (parts.length < 4) {
-            out.println(tag + " BAD Invalid STATUS command");
-            return;
-        }
-
-        String folderName = parts[2].replace("\"", "");
-        com.mailserver.domain.User user = userRepository.findByEmail(username).block();
-        if (user == null) {
-            out.println(tag + " NO User not found");
-            return;
-        }
-
-        com.mailserver.domain.Folder folder = folderRepository.findByUserIdAndName(user.getId(), folderName).block();
-        if (folder == null) {
-            out.println(tag + " NO [NONEXISTENT] Mailbox does not exist");
-            return;
-        }
-
-        long messageCount = messageRepository.findByFolderId(folder.getId(),
-                org.springframework.data.domain.PageRequest.of(0, 1)).count().block();
-        long unreadCount = messageRepository.countUnreadByFolderId(folder.getId()).block();
-
-        out.println("* STATUS " + folderName + " (MESSAGES " + messageCount + " UNSEEN " + unreadCount + " UIDNEXT " + (messageCount + 1) + " UIDVALIDITY 1)");
-        out.println(tag + " OK STATUS completed");
-    }
-
-    private String[] parseCommand(String line) {
-        if (line == null || line.trim().isEmpty()) return null;
-
-        line = line.trim();
-        int spaceIndex = line.indexOf(' ');
-        if (spaceIndex == -1) return new String[]{line, ""};
-
-        String tag = line.substring(0, spaceIndex);
-        String rest = line.substring(spaceIndex + 1).trim();
-
-        // Разбираем команду и аргументы
-        String[] parts = new String[20]; // Максимум 20 аргументов
-        parts[0] = tag;
-        int index = 1;
-
-        int i = 0;
-        while (i < rest.length() && index < parts.length) {
-            if (rest.charAt(i) == '"') {
-                // Строка в кавычках
-                int end = rest.indexOf('"', i + 1);
-                if (end == -1) break;
-                parts[index++] = rest.substring(i + 1, end);
-                i = end + 1;
-            } else if (Character.isWhitespace(rest.charAt(i))) {
-                i++;
-            } else {
-                int end = rest.indexOf(' ', i);
-                if (end == -1) end = rest.length();
-                parts[index++] = rest.substring(i, end);
-                i = end;
-            }
-        }
-
-        // Обрезаем массив до нужного размера
-        String[] result = new String[index];
-        System.arraycopy(parts, 0, result, 0, index);
-        return result;
-    }
-
-    private String formatImapDate(Instant instant) {
-        if (instant == null) return "";
-        // Формат IMAP: "dd-MMM-yyyy hh:mm:ss +0000"
-        String[] months = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
-                           "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
-        java.time.LocalDate date = instant.atZone(java.time.ZoneOffset.UTC).toLocalDate();
-        java.time.LocalTime time = instant.atZone(java.time.ZoneOffset.UTC).toLocalTime();
-
-        return String.format("%02d-%s-%04d %02d:%02d:%02d +0000",
-                date.getDayOfMonth(), months[date.getMonthValue() - 1], date.getYear(),
-                time.getHour(), time.getMinute(), time.getSecond());
-    }
-
-    private String escapeString(String str) {
-        if (str == null) return "";
-        return str.replace("\\", "\\\\").replace("\"", "\\\"");
-    }
-
-    private String formatFlags(com.mailserver.domain.Message message) {
-        StringBuilder flags = new StringBuilder();
-        if (message.isRead()) flags.append("\\Seen ");
-        if (message.isFlagged()) flags.append("\\Flagged ");
-        if (message.isSpam()) flags.append("\\Deleted ");
-        return flags.toString().trim();
-    }
-}

backend/src/main/java/com/mailserver/config/JwtConfig.java

@@ -5,14 +5,17 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
+import java.nio.charset.StandardCharsets;
+
 @Configuration
 public class JwtConfig {
 
-    @Value("${jwt.secret:MailServerSecretKeyForJWTTokenGenerationMustBeLongEnough2024!}")
+    /** JWT_SECRET from the environment, at least 32 bytes; no default — a known key would let anyone log in. */
-    private String jwtSecret;
-
     @Bean
-    public JwtUtils jwtUtils() {
+    public JwtUtils jwtUtils(@Value("${jwt.secret:}") String jwtSecret) {
+        if (jwtSecret.getBytes(StandardCharsets.UTF_8).length < 32) {
+            throw new IllegalStateException("jwt.secret (JWT_SECRET) must be set, at least 32 bytes");
+        }
         return new JwtUtils(jwtSecret);
     }
 }

backend/src/main/java/com/mailserver/config/LoginGuardConfig.java

@@ -0,0 +1,74 @@
+package com.mailserver.config;
+
+import com.mailserver.security.LoginGuard;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.web.server.adapter.ForwardedHeaderTransformer;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/** Brute-force protection (one guard for SMTP, IMAP and the web) and whose X-Forwarded-* headers to believe. */
+@Configuration
+public class LoginGuardConfig {
+
+    @Bean
+    public LoginGuard loginGuard(@Value("${mailserver.login-guard.enabled:true}") boolean enabled,
+                                 @Value("${mailserver.login-guard.max-per-ip:10}") int maxPerIp,
+                                 @Value("${mailserver.login-guard.max-per-account:20}") int maxPerAccount,
+                                 @Value("${mailserver.login-guard.window:15m}") Duration window,
+                                 @Value("${mailserver.login-guard.block:15m}") Duration block,
+                                 @Value("${mailserver.login-guard.max-block:24h}") Duration maxBlock,
+                                 @Value("${mailserver.login-guard.known-ip-ttl:30d}") Duration knownIpTtl,
+                                 @Value("${mailserver.login-guard.trusted-ips:}") String trustedIps,
+                                 @Value("${mailserver.login-guard.failure-delay:1s}") Duration failureDelay) {
+        Set<String> trusted = Arrays.stream(trustedIps.split(","))
+                .map(String::trim).filter(s -> !s.isEmpty()).collect(Collectors.toUnmodifiableSet());
+        return new LoginGuard(new LoginGuard.Settings(enabled, maxPerIp, maxPerAccount, window, block, maxBlock,
+                knownIpTtl, trusted, failureDelay));
+    }
+
+    /**
+     * Replaces Boot's transformer (server.forward-headers-strategy=framework): X-Forwarded-* / Forwarded are believed
+     * only from a proxy in a private network (Jambotron's Caddy comes over the docker network / WireGuard). A request
+     * straight from the internet (the VM's public address) has them removed — otherwise anyone could put a new
+     * X-Forwarded-For into every login attempt and never hit the per-IP limit.
+     */
+    @Bean(name = "forwardedHeaderTransformer")
+    public ForwardedHeaderTransformer forwardedHeaderTransformer() {
+        return new TrustedProxyHeaderTransformer();
+    }
+
+    static final class TrustedProxyHeaderTransformer extends ForwardedHeaderTransformer {
+
+        private final ForwardedHeaderTransformer stripOnly = new ForwardedHeaderTransformer();
+
+        TrustedProxyHeaderTransformer() {
+            stripOnly.setRemoveOnly(true);
+        }
+
+        @Override
+        public ServerHttpRequest apply(ServerHttpRequest request) {
+            return privatePeer(request.getRemoteAddress()) ? super.apply(request) : stripOnly.apply(request);
+        }
+    }
+
+    /** Loopback, 10/8, 172.16/12, 192.168/16, link-local, IPv6 fc00::/7. */
+    static boolean privatePeer(InetSocketAddress peer) {
+        if (peer == null || peer.getAddress() == null) {
+            return false;
+        }
+        InetAddress a = peer.getAddress();
+        if (a.isLoopbackAddress() || a.isSiteLocalAddress() || a.isLinkLocalAddress()) {
+            return true;
+        }
+        byte[] b = a.getAddress();
+        return b.length == 16 && (b[0] & 0xfe) == 0xfc;
+    }
+}

backend/src/main/java/com/mailserver/config/MailAdmins.java

@@ -0,0 +1,36 @@
+package com.mailserver.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Who manages mailboxes (Settings → Mailboxes): {@code mailserver.admins} (comma separated), by default the first
+ * mailbox — {@code mailserver.admin.email}, or admin@<first domain>. No role in the database: the list lives in
+ * the configuration, so a stolen mailbox can not make itself an administrator.
+ */
+@Component
+public class MailAdmins {
+
+    private final Set<String> admins;
+
+    public MailAdmins(@Value("${mailserver.admins:}") String admins,
+                      @Value("${mailserver.admin.email:}") String firstMailbox,
+                      MailDomains domains) {
+        String list = !admins.isBlank() ? admins
+                : !firstMailbox.isBlank() ? firstMailbox
+                : "admin@" + domains.domains().iterator().next();
+        this.admins = Arrays.stream(list.split(","))
+                .map(a -> a.trim().toLowerCase(Locale.ROOT))
+                .filter(a -> !a.isEmpty())
+                .collect(Collectors.toUnmodifiableSet());
+    }
+
+    public boolean isAdmin(String email) {
+        return email != null && admins.contains(email.toLowerCase(Locale.ROOT));
+    }
+}

backend/src/main/java/com/mailserver/config/MailDomains.java

@@ -0,0 +1,51 @@
+package com.mailserver.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Domains whose mailboxes live on this server ({@code mailserver.domains}), and the optional catch-all mailbox
+ * ({@code mailserver.catch-all}): when set, mail to ANY address is stored there and nothing is delivered outside —
+ * a mail trap for dev/staging.
+ */
+@Component
+public class MailDomains {
+
+    private final Set<String> domains;
+    private final String catchAll;
+
+    public MailDomains(@Value("${mailserver.domains:localhost}") String domains,
+                       @Value("${mailserver.catch-all:}") String catchAll) {
+        this.domains = Arrays.stream(domains.split(","))
+                .map(d -> d.trim().toLowerCase(Locale.ROOT))
+                .filter(d -> !d.isEmpty())
+                .collect(Collectors.toUnmodifiableSet());
+        this.catchAll = catchAll.trim().toLowerCase(Locale.ROOT);
+        if (this.domains.isEmpty()) {
+            throw new IllegalStateException("mailserver.domains is empty");
+        }
+    }
+
+    public boolean isLocal(String address) {
+        return domains.contains(domainOf(address));
+    }
+
+    /** Mailbox that receives everything, or null. */
+    public String catchAll() {
+        return catchAll.isEmpty() ? null : catchAll;
+    }
+
+    public Set<String> domains() {
+        return domains;
+    }
+
+    public static String domainOf(String address) {
+        int at = address == null ? -1 : address.lastIndexOf('@');
+        return at < 0 ? "" : address.substring(at + 1).toLowerCase(Locale.ROOT);
+    }
+}

backend/src/main/java/com/mailserver/config/MailServerConfig.java

@@ -0,0 +1,87 @@
+package com.mailserver.config;
+
+import com.mailserver.security.LoginGuard;
+import com.mailserver.delivery.SmtpDeliveryClient;
+import com.mailserver.smtp.MailRouter;
+import com.mailserver.smtp.SmtpServer;
+import com.mailserver.smtp.SmtpTls;
+import io.netty.handler.ssl.SslContext;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+import java.nio.file.Path;
+import java.time.Duration;
+import java.util.Locale;
+
+/** SMTP server, outbound delivery client and the queue scheduler. */
+@Configuration
+@EnableScheduling
+public class MailServerConfig {
+
+    /**
+     * Certificate for SMTP TLS: mailserver.tls.cert-file + key-file (PEM), or a self-signed one in mailserver.tls.dir.
+     * mailserver.tls.enabled=false — no TLS at all.
+     */
+    @Bean
+    public SmtpTlsContext smtpTlsContext(@Value("${mailserver.tls.enabled:true}") boolean enabled,
+                                         @Value("${mailserver.tls.cert-file:}") String certFile,
+                                         @Value("${mailserver.tls.key-file:}") String keyFile,
+                                         @Value("${mailserver.tls.dir:./tls}") String dir,
+                                         @Value("${mailserver.smtp.hostname:localhost}") String hostname) throws Exception {
+        return new SmtpTlsContext(enabled ? SmtpTls.serverContext(certFile, keyFile, Path.of(dir), hostname) : null);
+    }
+
+    public record SmtpTlsContext(SslContext context) {
+    }
+
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    @ConditionalOnProperty(name = "mailserver.smtp.enabled", havingValue = "true", matchIfMissing = true)
+    public SmtpServer smtpServer(MailRouter router, SmtpTlsContext tls, LoginGuard guard,
+                                 @Value("${mailserver.smtp.host:0.0.0.0}") String host,
+                                 @Value("${mailserver.smtp.port:3025}") int port,
+                                 @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                                 @Value("${mailserver.smtp.max-message-bytes:26214400}") long maxBytes,
+                                 @Value("${mailserver.smtp.auth-without-tls:false}") boolean authWithoutTls,
+                                 @Value("${mailserver.smtp.idle-timeout:5m}") Duration idleTimeout) {
+        return new SmtpServer(new SmtpServer.Settings(host, port, hostname, maxBytes, authWithoutTls, idleTimeout,
+                tls.context(), false), router, guard);
+    }
+
+    /** Implicit TLS (RFC 8314, usually port 465) — only when mailserver.smtps.port is set and TLS is on. */
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    @ConditionalOnExpression("${mailserver.smtps.port:0} > 0 and ${mailserver.tls.enabled:true}")
+    public SmtpServer smtpsServer(MailRouter router, SmtpTlsContext tls, LoginGuard guard,
+                                  @Value("${mailserver.smtp.host:0.0.0.0}") String host,
+                                  @Value("${mailserver.smtps.port}") int port,
+                                  @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                                  @Value("${mailserver.smtp.max-message-bytes:26214400}") long maxBytes,
+                                  @Value("${mailserver.smtp.idle-timeout:5m}") Duration idleTimeout) {
+        return new SmtpServer(new SmtpServer.Settings(host, port, hostname, maxBytes, false, idleTimeout,
+                tls.context(), true), router, guard);
+    }
+
+    /**
+     * mailserver.outbound.mode: off | mx | smarthost. For smarthost — host, port, username, password,
+     * tls (starttls | ssl | none).
+     */
+    @Bean
+    public SmtpDeliveryClient smtpDeliveryClient(@Value("${mailserver.outbound.mode:off}") String mode,
+                                                 @Value("${mailserver.outbound.host:}") String host,
+                                                 @Value("${mailserver.outbound.port:587}") int port,
+                                                 @Value("${mailserver.outbound.username:}") String username,
+                                                 @Value("${mailserver.outbound.password:}") String password,
+                                                 @Value("${mailserver.outbound.tls:starttls}") String tls,
+                                                 @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                                                 @Value("${mailserver.outbound.timeout-ms:30000}") int timeoutMs) {
+        SmtpDeliveryClient.Mode m = SmtpDeliveryClient.Mode.valueOf(mode.trim().toUpperCase(Locale.ROOT));
+        if (m == SmtpDeliveryClient.Mode.SMARTHOST && host.isBlank()) {
+            throw new IllegalStateException("mailserver.outbound.mode=smarthost needs mailserver.outbound.host");
+        }
+        return new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(m, host, port, username, password,
+                SmtpDeliveryClient.Tls.valueOf(tls.trim().toUpperCase(Locale.ROOT)), hostname, timeoutMs, 25));
+    }
+}

backend/src/main/java/com/mailserver/config/SecurityConfig.java

@@ -2,11 +2,13 @@ package com.mailserver.config;
 
 import com.mailserver.security.JwtAuthenticationFilter;
 import org.springframework.context.annotation.Bean;
+import org.springframework.http.HttpStatus;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
 import org.springframework.security.config.web.server.SecurityWebFiltersOrder;
 import org.springframework.security.config.web.server.ServerHttpSecurity;
 import org.springframework.security.web.server.SecurityWebFilterChain;
+import org.springframework.security.web.server.authentication.HttpStatusServerEntryPoint;
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.cors.reactive.CorsConfigurationSource;
 import org.springframework.web.cors.reactive.UrlBasedCorsConfigurationSource;
@@ -16,15 +18,19 @@ import org.springframework.web.cors.reactive.UrlBasedCorsConfigurationSource;
 public class SecurityConfig {
 
     private final JwtAuthenticationFilter jwtAuthenticationFilter;
+    private final String corsOrigins;
 
-    public SecurityConfig(JwtAuthenticationFilter jwtAuthenticationFilter) {
+    public SecurityConfig(JwtAuthenticationFilter jwtAuthenticationFilter,
+                          @org.springframework.beans.factory.annotation.Value("${mailserver.cors.origins:}") String corsOrigins) {
         this.jwtAuthenticationFilter = jwtAuthenticationFilter;
+        this.corsOrigins = corsOrigins;
     }
 
     @Bean
     public CorsConfigurationSource corsConfigurationSource() {
         CorsConfiguration configuration = new CorsConfiguration();
-        configuration.setAllowedOrigins(java.util.Arrays.asList("http://localhost:4200", "http://localhost:4201"));
+        // The web client is served from the same origin; other origins only for development (ng serve)
+        configuration.setAllowedOrigins(java.util.Arrays.stream(corsOrigins.split(",")).map(String::trim).filter(o -> !o.isEmpty()).toList());
         configuration.setAllowedMethods(java.util.Arrays.asList("GET", "POST", "PUT", "DELETE", "OPTIONS"));
         configuration.setAllowedHeaders(java.util.Arrays.asList("Authorization", "Content-Type", "Accept", "X-Requested-With"));
         configuration.setAllowCredentials(true);
@@ -38,10 +44,17 @@ public class SecurityConfig {
     public SecurityWebFilterChain filterChain(ServerHttpSecurity http) {
         http
             .csrf(ServerHttpSecurity.CsrfSpec::disable)
+            // JWT only: without this an API call with no token gets 401 + "WWW-Authenticate: Basic",
+            // and the browser shows its own login popup where our mailbox password does not work
+            .httpBasic(ServerHttpSecurity.HttpBasicSpec::disable)
+            .formLogin(ServerHttpSecurity.FormLoginSpec::disable)
+            .exceptionHandling(e -> e.authenticationEntryPoint(new HttpStatusServerEntryPoint(HttpStatus.UNAUTHORIZED)))
             .cors(cors -> cors.configurationSource(corsConfigurationSource()))
             .authorizeExchange(exchange -> exchange
-                .pathMatchers("/api/login", "/api/register").permitAll()
+                .pathMatchers("/api/login", "/api/register", "/api/config", "/actuator/health").permitAll()
-                .anyExchange().authenticated()
+                .pathMatchers("/api/**", "/actuator/**").authenticated()
+                // the web client (static files, SPA routes)
+                .anyExchange().permitAll()
             )
             .addFilterAt(jwtAuthenticationFilter, SecurityWebFiltersOrder.AUTHENTICATION);
 

backend/src/main/java/com/mailserver/config/SmtpServerConfig.java

@@ -1,379 +0,0 @@
-package com.mailserver.config;
-
-import com.mailserver.service.DkimService;
-import com.mailserver.service.DmarcService;
-import com.mailserver.service.MailService;
-import com.mailserver.service.SmtpRelayService;
-import com.mailserver.service.SpfService;
-import jakarta.annotation.PostConstruct;
-import jakarta.annotation.PreDestroy;
-import jakarta.mail.MessagingException;
-import jakarta.mail.Session;
-import jakarta.mail.internet.AddressException;
-import jakarta.mail.internet.InternetAddress;
-import jakarta.mail.internet.MimeMessage;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.context.annotation.Configuration;
-import reactor.core.publisher.Mono;
-import reactor.core.publisher.Sinks;
-import reactor.netty.DisposableServer;
-import reactor.netty.tcp.TcpServer;
-
-import java.io.*;
-import java.nio.charset.StandardCharsets;
-import java.util.*;
-
-/**
- * Встроенный SMTP-сервер на Spring WebFlux (TcpServer).
- * Поддерживает команды: HELO/EHLO, MAIL FROM, RCPT TO, DATA, QUIT, RSET, NOOP.
- * Обрабатывает входящие письма и сохраняет их через MailService.
- */
-@Configuration
-public class SmtpServerConfig {
-
-    private static final Logger log = LoggerFactory.getLogger(SmtpServerConfig.class);
-
-    private final MailService mailService;
-    private final SmtpRelayService smtpRelayService;
-    private final DkimService dkimService;
-    private final SpfService spfService;
-    private final DmarcService dmarcService;
-
-    @Value("${mailserver.smtp.port:3025}")
-    private int smtpPort;
-
-    @Value("${mailserver.smtp.hostname:localhost}")
-    private String smtpHostname;
-
-    @Value("${mailserver.smtp.enabled:true}")
-    private boolean enabled;
-
-    private DisposableServer disposableServer;
-
-    private final Map<String, String> capabilities = new HashMap<>();
-
-    public SmtpServerConfig(MailService mailService, SmtpRelayService smtpRelayService,
-                            DkimService dkimService,
-                            SpfService spfService, DmarcService dmarcService) {
-        this.mailService = mailService;
-        this.smtpRelayService = smtpRelayService;
-        this.dkimService = dkimService;
-        this.spfService = spfService;
-        this.dmarcService = dmarcService;
-        capabilities.put("SIZE", "10485760");
-        capabilities.put("8BITMIME", "");
-        capabilities.put("ENHANCEDSTATUSCODES", "");
-        capabilities.put("PIPELINING", "");
-    }
-
-    @PostConstruct
-    public void start() {
-        if (!enabled) {
-            log.info("SMTP-сервер отключён (mailserver.smtp.enabled=false)");
-            return;
-        }
-        try {
-            disposableServer = TcpServer.create()
-                    .port(smtpPort)
-                    .handle((inbound, outbound) ->
-                            outbound.sendString(Mono.just("220 " + smtpHostname + " ESMTP ready\r\n"))
-                                    .then(handleSmtpSession(inbound, outbound))
-                    )
-                    .bind()
-                    .block(java.time.Duration.ofSeconds(10));
-            log.info("SMTP-сервер запущен на порту {} (хост: {})", smtpPort, smtpHostname);
-        } catch (Exception e) {
-            log.error("Не удалось запустить SMTP-сервер на порту {}: {}", smtpPort, e.getMessage());
-            // Не бросаем исключение, чтобы приложение могло стартовать без SMTP
-        }
-    }
-
-    @PreDestroy
-    public void stop() {
-        if (disposableServer != null) {
-            try {
-                disposableServer.dispose();
-            } catch (Exception e) {
-                log.warn("Ошибка при остановке SMTP-сервера: {}", e.getMessage());
-            }
-            log.info("SMTP-сервер остановлен");
-        }
-    }
-
-    private Mono<Void> handleSmtpSession(reactor.netty.NettyInbound inbound,
-                                         reactor.netty.NettyOutbound outbound) {
-        SmtpSession session = new SmtpSession();
-
-        return inbound.receive()
-                .asString(StandardCharsets.UTF_8)
-                .doOnNext(line -> log.debug("SMTP: команда: {}", line.trim()))
-                .concatMap(line -> {
-                    line = line.trim();
-                    if (line.isEmpty()) {
-                        return Mono.empty();
-                    }
-
-                    String[] parts = line.split("\\s+", 2);
-                    String command = parts[0].toUpperCase();
-                    String argument = parts.length > 1 ? parts[1] : "";
-
-                    switch (command) {
-                        case "HELO": {
-                            session.helo = true;
-                            session.ehlo = false;
-                            session.hostname = argument;
-                            return Mono.just("250 " + smtpHostname + " Hello " + argument + "\r\n");
-                        }
-                        case "EHLO": {
-                            session.helo = true;
-                            session.ehlo = true;
-                            session.hostname = argument;
-                            return Mono.just(buildEhloResponse(argument));
-                        }
-                        case "MAIL": {
-                            if (!session.helo) {
-                                return Mono.just("503 Hello required first\r\n");
-                            }
-                            String mailFrom = extractEmail(argument);
-                            if (mailFrom == null) {
-                                return Mono.just("501 Syntax: MAIL FROM:<address>\r\n");
-                            }
-                            session.mailFrom = mailFrom;
-                            return Mono.just("250 OK\r\n");
-                        }
-                        case "RCPT": {
-                            if (!session.helo) {
-                                return Mono.just("503 Hello required first\r\n");
-                            }
-                            if (session.mailFrom == null) {
-                                return Mono.just("503 MAIL required first\r\n");
-                            }
-                            String rcptTo = extractEmail(argument);
-                            if (rcptTo == null) {
-                                return Mono.just("501 Syntax: RCPT TO:<address>\r\n");
-                            }
-                            session.recipients.add(rcptTo);
-                            return Mono.just("250 OK\r\n");
-                        }
-                        case "DATA": {
-                            if (!session.helo) {
-                                return Mono.just("503 Hello required first\r\n");
-                            }
-                            if (session.mailFrom == null) {
-                                return Mono.just("503 MAIL required first\r\n");
-                            }
-                            if (session.recipients.isEmpty()) {
-                                return Mono.just("503 RCPT required first\r\n");
-                            }
-                            session.dataReady = true;
-                            return Mono.just("354 Start mail input; end with <CRLF>.<CRLF>\r\n");
-                        }
-                        case "QUIT": {
-                            session.quit = true;
-                            return Mono.just("221 " + smtpHostname + " Bye\r\n");
-                        }
-                        case "RSET": {
-                            session.reset();
-                            return Mono.just("250 OK\r\n");
-                        }
-                        case "NOOP":
-                            return Mono.just("250 OK\r\n");
-                        case "VRFY":
-                            return Mono.just("252 Cannot VRFY user but will accept message\r\n");
-                        case "EXPN":
-                            return Mono.just("252 Cannot EXPN user but will accept message\r\n");
-                        default: {
-                            // Если в режиме DATA, накапливаем тело
-                            if (session.dataReady) {
-                                if (line.equals(".")) {
-                                    session.dataReady = false;
-                                    String body = session.dataBody.toString();
-                                    for (String recipient : session.recipients) {
-                                        try {
-                                            processIncomingMail(session.mailFrom, recipient, body);
-                                        } catch (Exception e) {
-                                            log.error("SMTP: ошибка обработки письма для {}: {}", recipient, e.getMessage());
-                                        }
-                                    }
-                                    session.reset();
-                                    session.dataBody.setLength(0);
-                                    return Mono.just("250 OK: message accepted\r\n");
-                                } else {
-                                    if (line.startsWith(".")) {
-                                        session.dataBody.append(line.substring(1));
-                                    } else {
-                                        session.dataBody.append(line);
-                                    }
-                                    session.dataBody.append("\n");
-                                    return Mono.empty();
-                                }
-                            } else {
-                                return Mono.just("502 Command not implemented\r\n");
-                            }
-                        }
-                    }
-                })
-                .filter(s -> !s.isEmpty())
-                .transform(outbound::sendString)
-                .then();
-    }
-
-    private String buildEhloResponse(String hostname) {
-        StringBuilder sb = new StringBuilder();
-        sb.append("250-").append(smtpHostname).append(" Hello ").append(hostname).append("\r\n");
-        for (Map.Entry<String, String> cap : capabilities.entrySet()) {
-            if (cap.getValue() != null && !cap.getValue().isEmpty()) {
-                sb.append("250-").append(cap.getKey()).append(" ").append(cap.getValue()).append("\r\n");
-            } else {
-                sb.append("250-").append(cap.getKey()).append("\r\n");
-            }
-        }
-        sb.append("250 AUTH LOGIN PLAIN\r\n");
-        return sb.toString();
-    }
-
-    private void processIncomingMail(String from, String recipient, String body) {
-        try {
-            Properties props = new Properties();
-            Session mailSession = Session.getDefaultInstance(props);
-            ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes(StandardCharsets.UTF_8));
-            MimeMessage mimeMessage = new MimeMessage(mailSession, bais);
-
-            String senderEmail = from;
-            String senderName = null;
-            InternetAddress[] fromAddresses = (InternetAddress[]) mimeMessage.getFrom();
-            if (fromAddresses != null && fromAddresses.length > 0) {
-                InternetAddress fromAddr = fromAddresses[0];
-                senderEmail = fromAddr.getAddress();
-                senderName = fromAddr.getPersonal();
-            }
-
-            String subject = mimeMessage.getSubject();
-            if (subject == null) subject = "";
-
-            Object content = mimeMessage.getContent();
-            String messageBody;
-            boolean isHtml = false;
-
-            if (content instanceof String) {
-                messageBody = (String) content;
-            } else if (content instanceof jakarta.mail.internet.MimeMultipart) {
-                messageBody = extractTextFromMultipart((jakarta.mail.internet.MimeMultipart) content);
-                isHtml = messageBody != null && (messageBody.contains("<html") || messageBody.contains("<HTML"));
-            } else {
-                messageBody = content != null ? content.toString() : "";
-            }
-            if (messageBody == null) messageBody = "";
-
-            boolean dkimPassed = dkimService.verifyMessage(mimeMessage);
-            String dkimDomain = null;
-            if (dkimPassed) {
-                String[] dkimHeaders = mimeMessage.getHeader("DKIM-Signature");
-                if (dkimHeaders != null && dkimHeaders.length > 0 && !dkimHeaders[0].isEmpty()) {
-                    dkimDomain = extractDkimDomain(dkimHeaders[0]);
-                }
-            }
-
-            SpfService.SpfResult spfResult = spfService.checkSpf(senderEmail, "127.0.0.1");
-            boolean spfPassed = spfResult == SpfService.SpfResult.PASS;
-            log.info("SPF проверка для {}: {} ({})", senderEmail, spfResult, spfResult.getDescription());
-
-            DmarcService.DmarcResult dmarcResult = dmarcService.checkDmarc(
-                    senderEmail, "127.0.0.1", spfPassed, dkimPassed, dkimDomain);
-            log.info("DMARC проверка для {}: {} ({})", senderEmail, dmarcResult, dmarcResult.getDescription());
-
-            boolean isSpam = dmarcService.shouldMarkAsSpam(dmarcResult)
-                    || spfResult == SpfService.SpfResult.FAIL
-                    || spfResult == SpfService.SpfResult.SOFTFAIL;
-
-            if (isSpam) {
-                log.info("Письмо от {} помечено как спам (SPF: {}, DKIM: {}, DMARC: {})",
-                        senderEmail, spfResult, dkimPassed, dmarcResult);
-            }
-
-            mailService.receiveMessage(senderEmail, senderName, recipient, subject, messageBody, isHtml, isSpam).block();
-            log.info("SMTP: письмо сохранено от {} для {} (тема: {})", senderEmail, recipient, subject);
-
-        } catch (AddressException e) {
-            log.error("SMTP: ошибка адреса: {}", e.getMessage());
-        } catch (MessagingException e) {
-            log.error("SMTP: ошибка парсинга MIME: {}", e.getMessage());
-        } catch (IllegalArgumentException e) {
-            // Получатель не найден в системе — пытаемся доставить через SMTP релей
-            log.info("SMTP: получатель {} не найден в системе, пытаемся доставить через релей", recipient);
-            try {
-                // Формируем MIME-контент для релея
-                Properties props = new Properties();
-                Session mailSession = Session.getDefaultInstance(props);
-                ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes(StandardCharsets.UTF_8));
-                MimeMessage mimeMessage = new MimeMessage(mailSession, bais);
-
-                ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                mimeMessage.writeTo(baos);
-                String mimeContent = baos.toString(StandardCharsets.UTF_8);
-
-                smtpRelayService.relayMessage(from, recipient, mimeContent).block();
-            } catch (Exception relayEx) {
-                log.error("SMTP: релей не смог доставить письмо для {}: {}", recipient, relayEx.getMessage());
-            }
-        } catch (Exception e) {
-            log.error("SMTP: ошибка обработки письма: {}", e.getMessage(), e);
-        }
-    }
-
-    private String extractTextFromMultipart(jakarta.mail.internet.MimeMultipart multipart)
-            throws MessagingException, IOException {
-        StringBuilder text = new StringBuilder();
-        for (int i = 0; i < multipart.getCount(); i++) {
-            var bodyPart = multipart.getBodyPart(i);
-            String contentType = bodyPart.getContentType();
-            if (contentType != null && contentType.toLowerCase().contains("text")) {
-                Object partContent = bodyPart.getContent();
-                if (partContent instanceof String) {
-                    text.append(partContent);
-                } else if (partContent instanceof InputStream) {
-                    try (InputStream is = (InputStream) partContent) {
-                        text.append(is.toString());
-                    }
-                }
-            }
-        }
-        return text.toString();
-    }
-
-    private String extractDkimDomain(String dkimHeader) {
-        int index = dkimHeader.indexOf("d=");
-        if (index == -1) return null;
-        int start = index + 2;
-        int end = dkimHeader.indexOf(";", start);
-        if (end == -1) end = dkimHeader.length();
-        return dkimHeader.substring(start, end).trim();
-    }
-
-    private String extractEmail(String argument) {
-        int start = argument.indexOf('<');
-        int end = argument.indexOf('>');
-        if (start == -1 || end == -1) return null;
-        return argument.substring(start + 1, end).trim().toLowerCase();
-    }
-
-    private static class SmtpSession {
-        boolean helo = false;
-        boolean ehlo = false;
-        boolean quit = false;
-        String hostname;
-        String mailFrom;
-        List<String> recipients = new ArrayList<>();
-        boolean dataReady = false;
-        StringBuilder dataBody = new StringBuilder();
-
-        void reset() {
-            mailFrom = null;
-            recipients.clear();
-            dataReady = false;
-            dataBody.setLength(0);
-        }
-    }
-}

backend/src/main/java/com/mailserver/config/SpaWebFilter.java

@@ -0,0 +1,29 @@
+package com.mailserver.config;
+
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+
+/**
+ * Angular routes (/inbox, /message/5, /compose;to=a@b.c …) are pages of the web client: serve index.html for them.
+ * A last segment with a dot (before matrix parameters) is a file.
+ */
+@Component
+@Order(-100)
+public class SpaWebFilter implements WebFilter {
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
+        String path = exchange.getRequest().getPath().pathWithinApplication().value();
+        boolean page = exchange.getRequest().getMethod().matches("GET")
+                && !path.startsWith("/api") && !path.startsWith("/actuator")
+                && !path.equals("/") && !path.substring(path.lastIndexOf('/') + 1).split(";")[0].contains(".");
+        if (page) {
+            return chain.filter(exchange.mutate().request(exchange.getRequest().mutate().path("/index.html").build()).build());
+        }
+        return chain.filter(exchange);
+    }
+}

backend/src/main/java/com/mailserver/controller/AuthenticationController.java

@@ -1,53 +1,202 @@
 package com.mailserver.controller;
 
+import com.mailserver.config.MailAdmins;
+import com.mailserver.config.MailDomains;
+import com.mailserver.domain.User;
 import com.mailserver.dto.LoginRequest;
 import com.mailserver.dto.LoginResponse;
-import com.mailserver.domain.User;
+import com.mailserver.dto.PasswordChangeRequest;
+import com.mailserver.dto.ProfileResponse;
+import com.mailserver.dto.ProfileUpdateRequest;
+import com.mailserver.dto.RegisterRequest;
+import com.mailserver.service.MailService;
 import com.mailserver.service.UserService;
+import com.mailserver.security.LoginGuard;
 import com.mailserver.util.JwtUtils;
 import jakarta.validation.Valid;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
 import reactor.core.publisher.Mono;
 
+import java.net.InetSocketAddress;
+import java.time.Duration;
+import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 
+/** Login, registration, the logged-in user's profile and password; what the login page needs to know. */
 @RestController
 @RequestMapping("/api")
 public class AuthenticationController {
 
-    private final UserService userService;
+    private static final Logger log = LoggerFactory.getLogger(AuthenticationController.class);
-    private final JwtUtils jwtUtils;
+    /** Marker for "no such mailbox or wrong password": both look the same from outside. */
+    private static final User NO_USER = new User();
 
-    public AuthenticationController(UserService userService, JwtUtils jwtUtils) {
+    /** Service addresses nobody can register (RFC 2142 and ours). */
+    static final Set<String> RESERVED = Set.of("postmaster", "abuse", "mailer-daemon", "hostmaster", "webmaster",
+            "root", "admin", "noreply", "no-reply", "security", "support");
+
+    private final UserService userService;
+    private final MailService mailService;
+    private final JwtUtils jwtUtils;
+    private final MailDomains domains;
+    private final boolean registrationEnabled;
+    private final LoginGuard guard;
+    private final MailAdmins admins;
+
+    public AuthenticationController(UserService userService, MailService mailService, JwtUtils jwtUtils, MailDomains domains,
+                                    @Value("${mailserver.registration.enabled:false}") boolean registrationEnabled,
+                                    LoginGuard guard, MailAdmins admins) {
+        this.guard = guard;
+        this.admins = admins;
         this.userService = userService;
+        this.mailService = mailService;
         this.jwtUtils = jwtUtils;
+        this.domains = domains;
+        this.registrationEnabled = registrationEnabled;
+    }
+
+    /** Public: is registration open, and in which domains mailboxes can be created. */
+    @GetMapping("/config")
+    public Map<String, Object> config() {
+        return Map.of("registrationEnabled", registrationEnabled, "domains", domains.domains().stream().sorted().toList());
     }
 
     @PostMapping("/login")
-    public Mono<ResponseEntity<?>> login(@Valid @RequestBody Mono<LoginRequest> requestMono) {
+    public Mono<ResponseEntity<?>> login(@Valid @RequestBody Mono<LoginRequest> requestMono, ServerHttpRequest http) {
-        return requestMono.flatMap(request ->
+        String ip = clientIp(http);
-            userService.findByEmail(request.getEmail())
+        return requestMono.flatMap(request -> {
-                .switchIfEmpty(Mono.error(new IllegalArgumentException("Invalid credentials")))
+            String email = request.getEmail().trim().toLowerCase(Locale.ROOT);
+            Duration wait = guard.retryAfter(ip, email);
+            if (!wait.isZero()) {
+                log.warn("WEB {}: login as {} refused, blocked for {}", ip, email, LoginGuard.human(wait));
+                return Mono.just(tooMany(wait));
+            }
+            return userService.findByEmail(email)
+                .map(user -> userService.checkPassword(user, request.getPassword()) ? user : NO_USER)
+                .onErrorResume(IllegalArgumentException.class, e -> Mono.just(NO_USER))
+                .defaultIfEmpty(NO_USER)
                 .flatMap(user -> {
+                    if (user == NO_USER) {
+                        guard.failure(ip, email);
+                        log.warn("WEB {}: authentication failed for {}", ip, email);
+                        Mono<ResponseEntity<?>> answer = Mono.just(ResponseEntity.badRequest().body(Map.of("error", "Invalid credentials")));
+                        Duration delay = guard.failureDelay();
+                        return delay.isZero() ? answer : answer.delayElement(delay);
+                    }
+                    guard.success(ip, email);
                     if (!user.isActive()) {
                         return Mono.just(ResponseEntity.badRequest().body(Map.of("error", "User is deactivated")));
                     }
-                    if (!userService.checkPassword(user, request.getPassword())) {
+                    return Mono.just(ResponseEntity.ok(token(user)));
-                        return Mono.just(ResponseEntity.badRequest().body(Map.of("error", "Invalid credentials")));
+                });
-                    }
+        });
-                    String token = jwtUtils.generateToken(user.getEmail());
-                    LoginResponse response = new LoginResponse();
-                    response.setToken(token);
-                    response.setEmail(user.getEmail());
-                    return Mono.just(ResponseEntity.ok(response));
-                })
-                .onErrorResume(IllegalArgumentException.class, e ->
-                    Mono.just(ResponseEntity.badRequest().body(Map.of("error", "Invalid credentials")))
-                )
-        );
     }
+
+    /** New mailbox in one of our domains; logs in right away (the answer carries the token). */
+    @PostMapping("/register")
+    public Mono<ResponseEntity<?>> register(@Valid @RequestBody Mono<RegisterRequest> requestMono) {
+        if (!registrationEnabled) {
+            return Mono.just(ResponseEntity.status(HttpStatus.FORBIDDEN).body(Map.of("error", "Registration is closed")));
+        }
+        return requestMono.flatMap(request -> {
+            String email = request.getEmail().trim().toLowerCase(Locale.ROOT);
+            String local = email.substring(0, email.indexOf('@'));
+            if (!domains.isLocal(email)) {
+                return Mono.just(ResponseEntity.badRequest()
+                        .body(Map.of("error", "Mailboxes can only be created in: " + String.join(", ", domains.domains()))));
+            }
+            if (RESERVED.contains(local) || !local.matches("[a-z0-9]([a-z0-9._-]{0,62}[a-z0-9])?")) {
+                return Mono.just(ResponseEntity.badRequest()
+                        .body(Map.of("error", "This name is not available: letters, digits, dot, dash, underscore")));
+            }
+            return userService.register(email, request.getPassword(), request.getDisplayName())
+                    .map(user -> ResponseEntity.status(HttpStatus.CREATED).body((Object) token(user)))
+                    .onErrorResume(IllegalArgumentException.class, e ->
+                            Mono.just(ResponseEntity.badRequest().body(Map.of("error", "This mailbox already exists"))));
+        });
+    }
+
+    @GetMapping("/me")
+    public Mono<ProfileResponse> me(Mono<Authentication> auth) {
+        return user(auth).flatMap(this::profile);
+    }
+
+    @PutMapping("/me")
+    public Mono<ProfileResponse> updateMe(Mono<Authentication> auth, @Valid @RequestBody Mono<ProfileUpdateRequest> body) {
+        return user(auth).zipWith(body)
+                .flatMap(pair -> userService.updateDisplayName(pair.getT1(), pair.getT2().displayName()))
+                .flatMap(this::profile);
+    }
+
+    @PutMapping("/me/password")
+    public Mono<Map<String, String>> changePassword(Mono<Authentication> auth, @Valid @RequestBody Mono<PasswordChangeRequest> body,
+                                                    ServerHttpRequest http) {
+        String ip = clientIp(http);
+        return user(auth).zipWith(body)
+                .flatMap(pair -> {
+                    User user = pair.getT1();
+                    // Someone with a stolen session must not guess the current password either
+                    Duration wait = guard.retryAfter(ip, user.getEmail());
+                    if (!wait.isZero()) {
+                        return Mono.error(new ResponseStatusException(HttpStatus.TOO_MANY_REQUESTS,
+                                "Too many failed attempts, try again in " + LoginGuard.human(wait)));
+                    }
+                    if (!userService.checkPassword(user, pair.getT2().currentPassword())) {
+                        guard.failure(ip, user.getEmail());
+                    }
+                    return userService.changePassword(user, pair.getT2().currentPassword(), pair.getT2().newPassword());
+                })
+                .thenReturn(Map.of("message", "Password changed"));
+    }
+
+    private static ResponseEntity<?> tooMany(Duration wait) {
+        return ResponseEntity.status(HttpStatus.TOO_MANY_REQUESTS)
+                .header(HttpHeaders.RETRY_AFTER, String.valueOf(Math.max(1, (wait.toMillis() + 999) / 1000)))
+                .body(Map.of("error", "Too many failed logins, try again in " + LoginGuard.human(wait)));
+    }
+
+    /** Client address; behind Caddy it comes from X-Forwarded-For (server.forward-headers-strategy=framework). */
+    static String clientIp(ServerHttpRequest http) {
+        InetSocketAddress address = http.getRemoteAddress();
+        if (address == null) {
+            return "unknown";
+        }
+        return address.getAddress() != null ? address.getAddress().getHostAddress() : address.getHostString();
+    }
+
+    private Mono<ProfileResponse> profile(User user) {
+        return mailService.usedBytes(user.getId())
+                .map(used -> new ProfileResponse(user.getEmail(), user.getDisplayName(), used,
+                        user.getQuotaBytes() == null ? 0 : user.getQuotaBytes(), user.getCreatedAt(),
+                        admins.isAdmin(user.getEmail())));
+    }
+
+    private Mono<User> user(Mono<Authentication> auth) {
+        return auth.switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.UNAUTHORIZED)))
+                .flatMap(a -> userService.findByEmail(a.getName()))
+                .onErrorMap(IllegalArgumentException.class, e -> new ResponseStatusException(HttpStatus.UNAUTHORIZED));
+    }
+
+    private LoginResponse token(User user) {
+        LoginResponse response = new LoginResponse();
+        response.setToken(jwtUtils.generateToken(user.getEmail()));
+        response.setEmail(user.getEmail());
+        return response;
+    }
+
 }

backend/src/main/java/com/mailserver/controller/MailController.java

@@ -3,27 +3,30 @@ package com.mailserver.controller;
 import com.mailserver.dto.AttachmentResponse;
 import com.mailserver.dto.FolderResponse;
 import com.mailserver.dto.MessageResponse;
-import com.mailserver.dto.RegisterRequest;
+import com.mailserver.dto.DraftRequest;
+import com.mailserver.dto.FolderRequest;
+import com.mailserver.dto.MessageUpdateRequest;
 import com.mailserver.dto.SendRequest;
 import com.mailserver.service.MailService;
 import com.mailserver.service.UserService;
 import jakarta.validation.Valid;
-import org.springframework.core.io.buffer.DataBuffer;
-import org.springframework.core.io.buffer.DataBufferUtils;
-import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.codec.multipart.FilePart;
 import org.springframework.security.core.Authentication;
+import com.mailserver.service.SubmissionService;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PatchMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RequestPart;
 import org.springframework.web.bind.annotation.RestController;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -46,180 +49,149 @@ public class MailController {
 
     private final UserService userService;
     private final MailService mailService;
+    private final SubmissionService submissionService;
 
-    public MailController(UserService userService, MailService mailService) {
+    public MailController(UserService userService, MailService mailService, SubmissionService submissionService) {
         this.userService = userService;
         this.mailService = mailService;
+        this.submissionService = submissionService;
     }
 
-    private Mono<String> getCurrentUserEmail(Mono<Authentication> authenticationMono) {
+    private Mono<com.mailserver.domain.User> user(Mono<Authentication> auth) {
-        return authenticationMono.map(Authentication::getName);
+        return auth.flatMap(a -> userService.findByEmail(a.getName()));
     }
 
-    // --- Users ---
+    // --- Folders ---
-
-    @PostMapping("/register")
-    public Mono<?> register(@Valid @RequestBody Mono<RegisterRequest> requestMono) {
-        return requestMono.flatMap(request ->
-            userService.register(request.getEmail(), request.getPassword(), request.getDisplayName())
-                .map(user -> org.springframework.http.ResponseEntity.status(HttpStatus.CREATED)
-                        .body(Map.of("message", "User registered")))
-                .onErrorResume(IllegalArgumentException.class, e ->
-                    Mono.just(org.springframework.http.ResponseEntity.badRequest()
-                        .body(Map.of("error", e.getMessage()))))
-        );
-    }
 
     @GetMapping("/folders")
-    public Flux<FolderResponse> getFolders(Mono<Authentication> authenticationMono) {
+    public Flux<FolderResponse> getFolders(Mono<Authentication> auth) {
-        return authenticationMono.flatMapMany(auth ->
+        return user(auth).flatMapMany(user -> mailService.folders(user.getId()));
-            userService.findByEmail(auth.getName())
+    }
-                .flatMapMany(user -> userService.getFolders(user.getId()))
+
-        );
+    @PostMapping("/folders")
+    public Mono<ResponseEntity<FolderResponse>> createFolder(Mono<Authentication> auth, @Valid @RequestBody Mono<FolderRequest> body) {
+        return user(auth).zipWith(body)
+                .flatMap(pair -> mailService.createFolder(pair.getT1().getId(), pair.getT2().name()))
+                .map(folder -> ResponseEntity.status(HttpStatus.CREATED).body(folder));
+    }
+
+    @PutMapping("/folders/{id}")
+    public Mono<Map<String, String>> renameFolder(@PathVariable Long id, Mono<Authentication> auth,
+                                                  @Valid @RequestBody Mono<FolderRequest> body) {
+        return user(auth).zipWith(body)
+                .flatMap(pair -> mailService.renameFolder(id, pair.getT1().getId(), pair.getT2().name()))
+                .thenReturn(Map.of("message", "Folder renamed"));
+    }
+
+    /** Own folder only; its messages go to the Trash. */
+    @DeleteMapping("/folders/{id}")
+    public Mono<Map<String, String>> deleteFolder(@PathVariable Long id, Mono<Authentication> auth) {
+        return user(auth).flatMap(user -> mailService.deleteFolder(id, user.getId()))
+                .thenReturn(Map.of("message", "Folder deleted"));
+    }
+
+    /** Trash or Spam: removes all its messages for good. */
+    @DeleteMapping("/folders/{id}/messages")
+    public Mono<Map<String, Object>> emptyFolder(@PathVariable Long id, Mono<Authentication> auth) {
+        return user(auth).flatMap(user -> mailService.emptyFolder(id, user.getId()))
+                .map(count -> Map.<String, Object>of("deleted", count));
     }
 
     // --- Messages ---
 
+    /** Newest first, bodies cut to a preview. */
     @GetMapping("/messages")
-    public Flux<MessageResponse> getMessages(
+    public Flux<MessageResponse> getMessages(Mono<Authentication> auth, @RequestParam Long folderId,
-            Mono<Authentication> authenticationMono,
+                                             @RequestParam(defaultValue = "" + MailService.LIST_LIMIT) int limit) {
-            @RequestParam Long folderId,
+        return user(auth).flatMapMany(user -> mailService.listMessages(folderId, user.getId(), limit));
-            @RequestParam(defaultValue = "0") int page,
-            @RequestParam(defaultValue = "20") int size) {
-        return authenticationMono.flatMapMany(auth ->
-            userService.findByEmail(auth.getName())
-                .flatMapMany(user -> mailService.getMessages(folderId, user.getId(), page, size))
-        );
     }
 
     @GetMapping("/messages/search")
     public Flux<MessageResponse> searchMessages(
-            Mono<Authentication> authenticationMono,
+            Mono<Authentication> auth,
             @RequestParam Long folderId,
             @RequestParam(required = false) String keyword,
             @RequestParam(required = false) String subject,
             @RequestParam(required = false) String body,
             @RequestParam(required = false) String sender,
-            @RequestParam(required = false) String recipient,
+            @RequestParam(required = false) String recipient) {
-            @RequestParam(defaultValue = "0") int page,
+        return user(auth).flatMapMany(user -> keyword != null && !keyword.isBlank()
-            @RequestParam(defaultValue = "20") int size) {
+                ? mailService.searchMessages(folderId, user.getId(), keyword.trim(), 0, MailService.LIST_LIMIT)
-        return authenticationMono.flatMapMany(auth ->
+                : mailService.searchMessagesWithFilters(folderId, user.getId(), subject, body, sender, recipient,
-            userService.findByEmail(auth.getName())
+                        0, MailService.LIST_LIMIT));
-                .flatMapMany(user -> {
-                    if (keyword != null && !keyword.trim().isEmpty()) {
-                        return mailService.searchMessages(folderId, user.getId(), keyword.trim(), page, size);
-                    }
-                    return mailService.searchMessagesWithFilters(folderId, user.getId(),
-                            subject, body, sender, recipient, page, size);
-                })
-        );
     }
 
     @GetMapping("/messages/{id}")
-    public Mono<MessageResponse> getMessage(@PathVariable Long id, Mono<Authentication> authenticationMono) {
+    public Mono<MessageResponse> getMessage(@PathVariable Long id, Mono<Authentication> auth) {
-        return authenticationMono.flatMap(auth ->
+        return user(auth).flatMap(user -> mailService.getMessage(id, user.getId()));
-            userService.findByEmail(auth.getName())
-                .flatMap(user -> mailService.getMessage(id, user.getId()))
-        );
     }
 
-    @PostMapping("/send")
+    /** read / flagged / folderId — only the fields that are set. */
-    public Mono<Object> sendMessage(
+    @PatchMapping("/messages/{id}")
-            Mono<Authentication> authenticationMono,
+    public Mono<MessageResponse> updateMessage(@PathVariable Long id, Mono<Authentication> auth,
-            @Valid @RequestBody Mono<SendRequest> requestMono) {
+                                               @RequestBody Mono<MessageUpdateRequest> body) {
-        return authenticationMono.zipWith(requestMono)
+        return user(auth).zipWith(body)
-                .flatMap(pair -> {
+                .flatMap(pair -> mailService.updateMessage(id, pair.getT1().getId(), pair.getT2()));
-                    String email = pair.getT1().getName();
-                    SendRequest request = pair.getT2();
-                    return mailService.sendMessage(email, request)
-                        .map(response -> (Object) org.springframework.http.ResponseEntity.ok(response))
-                        .onErrorResume(e -> {
-                            log.error("Ошибка при отправке письма: {}", e.getMessage(), e);
-                            return Mono.just((Object) org.springframework.http.ResponseEntity.badRequest()
-                                .body(Map.of("error", e.getMessage())));
-                        });
-                });
     }
 
     @PutMapping("/messages/{id}/read")
-    public Mono<?> markAsRead(@PathVariable Long id, Mono<Authentication> authenticationMono) {
+    public Mono<Map<String, String>> markAsRead(@PathVariable Long id, Mono<Authentication> auth) {
-        return authenticationMono.flatMap(auth ->
+        return user(auth).flatMap(user -> mailService.markAsRead(id, user.getId()))
-            userService.findByEmail(auth.getName())
+                .thenReturn(Map.of("message", "Marked as read"));
-                .flatMap(user -> mailService.markAsRead(id, user.getId())
-                    .then(Mono.just(org.springframework.http.ResponseEntity.ok(Map.of("message", "Marked as read")))))
-        );
     }
 
+    /** Into the Trash; from the Trash — for good. */
     @DeleteMapping("/messages/{id}")
-    public Mono<?> deleteMessage(@PathVariable Long id, Mono<Authentication> authenticationMono) {
+    public Mono<Map<String, String>> deleteMessage(@PathVariable Long id, Mono<Authentication> auth) {
-        return authenticationMono.flatMap(auth ->
+        return user(auth).flatMap(user -> mailService.deleteMessage(id, user.getId()))
-            userService.findByEmail(auth.getName())
+                .thenReturn(Map.of("message", "Message deleted"));
-                .flatMap(user -> mailService.deleteMessage(id, user.getId())
-                    .then(Mono.just(org.springframework.http.ResponseEntity.ok(Map.of("message", "Message deleted")))))
-        );
     }
 
-    // --- Simulate incoming message (для тестов) ---
+    @PostMapping("/send")
+    public Mono<MessageResponse> sendMessage(Mono<Authentication> auth, @Valid @RequestBody Mono<SendRequest> requestMono) {
+        return auth.zipWith(requestMono)
+                .flatMap(pair -> submissionService.send(pair.getT1().getName(), pair.getT2()));
+    }
 
-    @PostMapping("/simulate/receive")
+    // --- Drafts ---
-    public Mono<?> simulateReceive(@RequestBody Mono<Map<String, String>> bodyMono) {
+
-        return bodyMono.flatMap(body ->
+    @PostMapping("/drafts")
-            mailService.receiveMessage(
+    public Mono<MessageResponse> createDraft(Mono<Authentication> auth, @Valid @RequestBody Mono<DraftRequest> body) {
-                    body.get("senderEmail"),
+        return user(auth).zipWith(body).flatMap(pair -> mailService.saveDraft(pair.getT1(), null, pair.getT2()));
-                    body.get("senderName"),
+    }
-                    body.get("recipientEmail"),
+
-                    body.get("subject"),
+    @PutMapping("/drafts/{id}")
-                    body.get("body"),
+    public Mono<MessageResponse> updateDraft(@PathVariable Long id, Mono<Authentication> auth,
-                    "true".equals(body.get("html"))
+                                             @Valid @RequestBody Mono<DraftRequest> body) {
-            )
+        return user(auth).zipWith(body).flatMap(pair -> mailService.saveDraft(pair.getT1(), id, pair.getT2()));
-            .then(Mono.just(org.springframework.http.ResponseEntity.ok(Map.of("message", "Message received"))))
-            .onErrorResume(e ->
-                Mono.just(org.springframework.http.ResponseEntity.badRequest().body(Map.of("error", e.getMessage()))))
-        );
     }
 
     // --- Attachments ---
 
+    /** A file for a draft (form field "file"); stored on disk, the draft gets the record. */
     @PostMapping(value = "/messages/{messageId}/attachments", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
-    public Mono<?> uploadAttachment(
+    public Mono<ResponseEntity<AttachmentResponse>> uploadAttachment(
             @PathVariable Long messageId,
-            Mono<Authentication> authenticationMono,
+            Mono<Authentication> auth,
-            @RequestBody Mono<Flux<FilePart>> filePartsMono) {
+            @RequestPart("file") Mono<FilePart> fileMono) {
-        return authenticationMono.zipWith(filePartsMono)
+        return user(auth).zipWith(fileMono).flatMap(pair -> {
-                .flatMap(pair -> {
+            var user = pair.getT1();
-                    String email = pair.getT1().getName();
+            FilePart file = pair.getT2();
-                    return userService.findByEmail(email)
+            String originalFilename = safeFilename(file.filename());
-                        .flatMapMany(user -> pair.getT2())
+            Path filePath = Paths.get(mailService.getAttachmentsDir(), UUID.randomUUID() + "_" + originalFilename);
-                        .next()
+            String contentType = file.headers().getContentType() != null
-                        .flatMap(file -> {
+                    ? file.headers().getContentType().toString() : "application/octet-stream";
-                            String originalFilename = file.filename();
+            // the draft must be the user's before anything is written
-                            String uniqueName = UUID.randomUUID() + "_" + originalFilename;
+            return mailService.ownedDraft(messageId, user.getId())
-                            Path filePath = Paths.get(mailService.getAttachmentsDir(), uniqueName);
+                    .then(Mono.fromCallable(() -> Files.createDirectories(filePath.getParent()))
-                            try {
+                            .subscribeOn(reactor.core.scheduler.Schedulers.boundedElastic()))
-                                Files.createDirectories(filePath.getParent());
+                    .then(file.transferTo(filePath))
-                            } catch (IOException e) {
+                    .then(Mono.fromCallable(() -> Files.size(filePath))
-                                return Mono.error(new RuntimeException("Failed to create directory", e));
+                            .subscribeOn(reactor.core.scheduler.Schedulers.boundedElastic()))
-                            }
+                    .flatMap(size -> mailService.saveAttachmentReactive(messageId, user.getId(), originalFilename,
-
+                            contentType, size, filePath.toString()))
-                            return DataBufferUtils.join(file.content())
+                    .map(response -> ResponseEntity.status(HttpStatus.CREATED).body(response));
-                                    .flatMap(dataBuffer -> {
+        });
-                                        byte[] bytes = new byte[dataBuffer.readableByteCount()];
-                                        dataBuffer.read(bytes);
-                                        DataBufferUtils.release(dataBuffer);
-                                        try {
-                                            Files.write(filePath, bytes);
-                                        } catch (IOException e) {
-                                            return Mono.error(new RuntimeException("Failed to save file", e));
-                                        }
-                                        return userService.findByEmail(email)
-                                            .flatMap(user -> mailService.saveAttachmentReactive(
-                                                messageId, user.getId(),
-                                                originalFilename, file.headers().getContentType().toString(),
-                                                bytes.length, filePath.toString()))
-                                            .map(response -> org.springframework.http.ResponseEntity.status(HttpStatus.CREATED).body(response));
-                                    });
-                        });
-                });
     }
 
     @GetMapping("/messages/{messageId}/attachments")
@@ -233,39 +205,40 @@ public class MailController {
     }
 
     @GetMapping("/attachments/{attachmentId}/download")
-    public Mono<Object> downloadAttachment(
+    public Mono<ResponseEntity<byte[]>> downloadAttachment(
             @PathVariable Long attachmentId,
             Mono<Authentication> authenticationMono) {
-        return authenticationMono.flatMap(auth ->
+        return authenticationMono.flatMap(auth -> userService.findByEmail(auth.getName()))
-            userService.findByEmail(auth.getName())
+                .flatMap(user -> mailService.getAttachment(attachmentId, user.getId()))
-                .flatMap(user -> {
+                .flatMap(attachment -> Mono.fromCallable(() -> Files.readAllBytes(Paths.get(attachment.getFilePath())))
-                    try {
+                        .subscribeOn(reactor.core.scheduler.Schedulers.boundedElastic())
-                        AttachmentResponse info = mailService.getAttachmentInfo(attachmentId, user.getId());
+                        .map(bytes -> ResponseEntity.ok()
-                        Path filePath = Paths.get(mailService.getAttachmentFilePath(attachmentId, user.getId()));
+                                .header(HttpHeaders.CONTENT_DISPOSITION, org.springframework.http.ContentDisposition.attachment()
-                        byte[] bytes;
+                                        .filename(attachment.getFilename(), java.nio.charset.StandardCharsets.UTF_8).build().toString())
-                        try {
+                                .contentType(contentType(attachment.getContentType()))
-                            bytes = Files.readAllBytes(filePath);
+                                .body(bytes)));
-                        } catch (IOException e) {
+    }
-                            return Mono.just((Object) org.springframework.http.ResponseEntity.badRequest()
+
-                                    .body(Map.of("error", "Failed to read file: " + e.getMessage())));
+    private static MediaType contentType(String value) {
-                        }
+        try {
-                        DataBuffer buffer = new DefaultDataBufferFactory().wrap(bytes);
+            return value == null ? MediaType.APPLICATION_OCTET_STREAM : MediaType.parseMediaType(value);
-                        return Mono.just((Object) org.springframework.http.ResponseEntity.ok()
+        } catch (org.springframework.util.InvalidMimeTypeException e) {
-                                .header(HttpHeaders.CONTENT_DISPOSITION,
+            return MediaType.APPLICATION_OCTET_STREAM;
-                                        "attachment; filename=\"" + info.getFilename() + "\"")
+        }
-                                .contentType(MediaType.parseMediaType(
+    }
-                                        info.getContentType() != null ? info.getContentType() : "application/octet-stream"))
+
-                                .body(buffer)
+    /** Only the last path segment, no control characters — a file name cannot leave the attachments folder. */
-                        );
+    public static String safeFilename(String name) {
-                    } catch (IllegalArgumentException e) {
+        String base = name == null ? "" : name.replace('\\', '/');
-                        return Mono.just((Object) org.springframework.http.ResponseEntity.badRequest().body(Map.of("error", e.getMessage())));
+        base = base.substring(base.lastIndexOf('/') + 1).replaceAll("[\\p{Cntrl}\"]", "").trim();
-                    }
+        if (base.isEmpty() || base.equals(".") || base.equals("..")) {
-                })
+            return "file";
-        );
+        }
+        return base.length() > 200 ? base.substring(base.length() - 200) : base;
     }
 
     @DeleteMapping("/attachments/{attachmentId}")
-    public Mono<?> deleteAttachment(
+    public Mono<ResponseEntity<?>> deleteAttachment(
             @PathVariable Long attachmentId,
             Mono<Authentication> authenticationMono) {
         return authenticationMono.flatMap(auth ->
@@ -333,7 +306,7 @@ public class MailController {
     }
 
     @DeleteMapping("/contacts/{id}")
-    public Mono<?> deleteContact(
+    public Mono<ResponseEntity<?>> deleteContact(
             @PathVariable Long id,
             Mono<Authentication> authenticationMono) {
         return authenticationMono.flatMap(auth ->

backend/src/main/java/com/mailserver/controller/MailboxAdminController.java

@@ -0,0 +1,184 @@
+package com.mailserver.controller;
+
+import com.mailserver.config.MailAdmins;
+import com.mailserver.config.MailDomains;
+import com.mailserver.domain.User;
+import com.mailserver.dto.LoginResponse;
+import com.mailserver.service.MailService;
+import com.mailserver.service.UserService;
+import com.mailserver.util.JwtUtils;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.security.SecureRandom;
+import java.time.Instant;
+import java.util.Base64;
+import java.util.Comparator;
+import java.util.Locale;
+import java.util.regex.Pattern;
+
+/**
+ * Mailboxes of this server for its administrators ({@link MailAdmins}): list, create (no-reply@, monitor@,
+ * support@ — registration stays closed), new password, switch off. A generated password is returned once, in the
+ * answer — it is not logged.
+ */
+@RestController
+@RequestMapping("/api/admin/mailboxes")
+public class MailboxAdminController {
+
+    private static final Logger log = LoggerFactory.getLogger(MailboxAdminController.class);
+    private static final Pattern LOCAL_PART = Pattern.compile("[a-z0-9](?:[a-z0-9._+-]{0,62}[a-z0-9])?");
+    private static final int MIN_PASSWORD = 10;
+
+    public record MailboxView(Long id, String email, String displayName, boolean active, boolean admin,
+                              long usedBytes, long quotaBytes, Instant createdAt) {
+    }
+
+    /** @param password empty — the server generates one and returns it once */
+    public record CreateRequest(@NotBlank @Size(max = 254) String email, @Size(max = 100) String displayName,
+                                @Size(max = 200) String password) {
+    }
+
+    public record PasswordRequest(@Size(max = 200) String password) {
+    }
+
+    public record ActiveRequest(boolean active) {
+    }
+
+    /** @param password the generated password, or null when the administrator chose it */
+    public record Created(MailboxView mailbox, String password) {
+    }
+
+    private final UserService users;
+    private final MailService mail;
+    private final MailDomains domains;
+    private final MailAdmins admins;
+    private final JwtUtils jwt;
+
+    public MailboxAdminController(UserService users, MailService mail, MailDomains domains, MailAdmins admins, JwtUtils jwt) {
+        this.jwt = jwt;
+        this.users = users;
+        this.mail = mail;
+        this.domains = domains;
+        this.admins = admins;
+    }
+
+    @GetMapping
+    public Flux<MailboxView> list(Mono<Authentication> auth) {
+        return admin(auth).thenMany(users.all())
+                .concatMap(this::view)
+                .sort(Comparator.comparing(MailboxView::email));
+    }
+
+    @PostMapping
+    @ResponseStatus(HttpStatus.CREATED)
+    public Mono<Created> create(Mono<Authentication> auth, @RequestBody Mono<CreateRequest> body) {
+        return admin(auth).then(body).flatMap(request -> {
+            String email = request.email() == null ? "" : request.email().trim().toLowerCase(Locale.ROOT);
+            int at = email.lastIndexOf('@');
+            if (at <= 0 || !LOCAL_PART.matcher(email.substring(0, at)).matches()) {
+                return Mono.error(bad("Not a mailbox address: " + email));
+            }
+            if (!domains.isLocal(email)) {
+                return Mono.error(bad("Mailboxes can be created only in " + String.join(", ", domains.domains().stream().sorted().toList())));
+            }
+            String chosen = request.password() == null ? "" : request.password();
+            if (!chosen.isEmpty() && chosen.length() < MIN_PASSWORD) {
+                return Mono.error(bad("Password: at least " + MIN_PASSWORD + " characters, or leave it empty to generate one"));
+            }
+            String password = chosen.isEmpty() ? randomPassword() : chosen;
+            return users.register(email, password, request.displayName())
+                    .onErrorMap(IllegalArgumentException.class, e -> new ResponseStatusException(HttpStatus.CONFLICT, "This mailbox already exists"))
+                    .doOnNext(user -> log.info("Mailbox created by administrator: {}", email))
+                    .flatMap(this::view)
+                    .map(view -> new Created(view, chosen.isEmpty() ? password : null));
+        });
+    }
+
+    /** New password: the given one, or a generated one returned once. */
+    @PostMapping("/{id}/password")
+    public Mono<Created> password(Mono<Authentication> auth, @PathVariable Long id, @RequestBody Mono<PasswordRequest> body) {
+        return admin(auth).then(body.defaultIfEmpty(new PasswordRequest(null))).flatMap(request -> {
+            String chosen = request.password() == null ? "" : request.password();
+            if (!chosen.isEmpty() && chosen.length() < MIN_PASSWORD) {
+                return Mono.error(bad("Password: at least " + MIN_PASSWORD + " characters, or leave it empty to generate one"));
+            }
+            String password = chosen.isEmpty() ? randomPassword() : chosen;
+            return mailbox(id)
+                    .flatMap(user -> users.setPassword(user, password))
+                    .doOnNext(user -> log.info("Password of {} set by administrator", user.getEmail()))
+                    .flatMap(this::view)
+                    .map(view -> new Created(view, chosen.isEmpty() ? password : null));
+        });
+    }
+
+    /**
+     * Administrator opens a mailbox without its password (Settings → MAILBOXES → Open): a session of that mailbox.
+     * Every opening is logged — who opened which mailbox.
+     */
+    @PostMapping("/{id}/open")
+    public Mono<LoginResponse> open(Mono<Authentication> auth, @PathVariable Long id) {
+        return admin(auth).flatMap(me -> mailbox(id).map(user -> {
+            log.warn("Administrator {} opened mailbox {}", me, user.getEmail());
+            LoginResponse response = new LoginResponse();
+            response.setToken(jwt.generateToken(user.getEmail()));
+            response.setEmail(user.getEmail());
+            return response;
+        }));
+    }
+
+    /** Switched off: no login (web, SMTP, IMAP); mail to it is still received. */
+    @PutMapping("/{id}/active")
+    public Mono<MailboxView> active(Mono<Authentication> auth, @PathVariable Long id, @RequestBody Mono<ActiveRequest> body) {
+        return admin(auth).flatMap(me -> body.flatMap(request -> mailbox(id).flatMap(user -> {
+            if (!request.active() && user.getEmail().equalsIgnoreCase(me)) {
+                return Mono.error(bad("You can not switch off your own mailbox"));
+            }
+            log.info("Mailbox {} {} by administrator", user.getEmail(), request.active() ? "switched on" : "switched off");
+            return users.setActive(user, request.active());
+        }))).flatMap(this::view);
+    }
+
+    private Mono<String> admin(Mono<Authentication> auth) {
+        return auth.switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.UNAUTHORIZED)))
+                .map(Authentication::getName)
+                .filter(admins::isAdmin)
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.FORBIDDEN, "Only for mail administrators")));
+    }
+
+    private Mono<User> mailbox(Long id) {
+        return users.byId(id).switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND, "Mailbox not found")));
+    }
+
+    private Mono<MailboxView> view(User user) {
+        return mail.usedBytes(user.getId()).defaultIfEmpty(0L)
+                .map(used -> new MailboxView(user.getId(), user.getEmail(), user.getDisplayName(), user.isActive(),
+                        admins.isAdmin(user.getEmail()), used, user.getQuotaBytes() == null ? 0 : user.getQuotaBytes(),
+                        user.getCreatedAt()));
+    }
+
+    private static ResponseStatusException bad(String message) {
+        return new ResponseStatusException(HttpStatus.BAD_REQUEST, message);
+    }
+
+    static String randomPassword() {
+        byte[] bytes = new byte[18];
+        new SecureRandom().nextBytes(bytes);
+        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
+    }
+}

backend/src/main/java/com/mailserver/delivery/DeliveryWorker.java

@@ -0,0 +1,96 @@
+package com.mailserver.delivery;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+
+/**
+ * Sends queued messages. Temporary failure (4xx, no connection, DNS) — retry later with growing pauses,
+ * about 22 hours in total; permanent failure (5xx) or retries used up — FAILED and a bounce to the sender's inbox.
+ * Runs on the scheduler thread: blocking here is fine, it is not the network event loop.
+ */
+@Component
+public class DeliveryWorker {
+
+    private static final Logger log = LoggerFactory.getLogger(DeliveryWorker.class);
+
+    static final List<Duration> RETRY_PAUSES = List.of(
+            Duration.ofMinutes(1), Duration.ofMinutes(5), Duration.ofMinutes(15), Duration.ofHours(1),
+            Duration.ofHours(3), Duration.ofHours(6), Duration.ofHours(12));
+    private static final int BATCH = 20;
+
+    /** Tells the sender that a message did not reach someone. */
+    public interface BounceSender {
+        void bounce(OutboundMessage message, String reason);
+    }
+
+    private final OutboundRepository repository;
+    private final SmtpDeliveryClient client;
+    private final BounceSender bounces;
+
+    public DeliveryWorker(OutboundRepository repository, SmtpDeliveryClient client, BounceSender bounces) {
+        this.repository = repository;
+        this.client = client;
+        this.bounces = bounces;
+    }
+
+    @Scheduled(initialDelayString = "${mailserver.queue.initial-delay-ms:5000}", fixedDelayString = "${mailserver.queue.poll-ms:15000}")
+    public void deliverDue() {
+        List<OutboundMessage> due = repository.findDue(Instant.now(), BATCH).collectList().block();
+        if (due == null) {
+            return;
+        }
+        for (OutboundMessage message : due) {
+            try {
+                attempt(message, Instant.now());
+            } catch (RuntimeException e) {
+                log.error("Queue item {} not processed: {}", message.getId(), e.toString());
+            }
+        }
+    }
+
+    void attempt(OutboundMessage message, Instant now) {
+        SmtpDeliveryClient.Result result = client.deliver(message.getMailFrom(), message.getRcptTo(), message.getMessage());
+        message.setAttempts(message.getAttempts() + 1);
+        message.setLastError(result.outcome() == SmtpDeliveryClient.Outcome.DELIVERED ? null : truncate(result.detail()));
+        switch (result.outcome()) {
+            case DELIVERED -> finish(message, OutboundMessage.DELIVERED, now);
+            case PERMANENT -> fail(message, now, result.detail());
+            case TEMPORARY -> {
+                if (message.getAttempts() > RETRY_PAUSES.size()) {
+                    fail(message, now, "gave up after " + message.getAttempts() + " attempts: " + result.detail());
+                } else {
+                    message.setNextAttemptAt(now.plus(RETRY_PAUSES.get(message.getAttempts() - 1)));
+                    repository.save(message).block();
+                    log.info("Queue item {} to {}: retry at {} ({})", message.getId(), message.getRcptTo(),
+                            message.getNextAttemptAt(), result.detail());
+                }
+            }
+        }
+    }
+
+    private void fail(OutboundMessage message, Instant now, String reason) {
+        finish(message, OutboundMessage.FAILED, now);
+        log.warn("Queue item {} to {} FAILED: {}", message.getId(), message.getRcptTo(), reason);
+        try {
+            bounces.bounce(message, reason);
+        } catch (RuntimeException e) {
+            log.error("Bounce for queue item {} not stored: {}", message.getId(), e.toString());
+        }
+    }
+
+    private void finish(OutboundMessage message, String status, Instant now) {
+        message.setStatus(status);
+        message.setFinishedAt(now);
+        repository.save(message).block();
+    }
+
+    private static String truncate(String text) {
+        return text == null || text.length() <= 1000 ? text : text.substring(0, 1000);
+    }
+}

backend/src/main/java/com/mailserver/delivery/OutboundMessage.java

@@ -0,0 +1,57 @@
+package com.mailserver.delivery;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.relational.core.mapping.Column;
+import org.springframework.data.relational.core.mapping.Table;
+
+import java.time.Instant;
+
+@Table("outbound_queue")
+public class OutboundMessage {
+
+    public static final String PENDING = "PENDING";
+    public static final String DELIVERED = "DELIVERED";
+    public static final String FAILED = "FAILED";
+
+    @Id
+    private Long id;
+    @Column("mail_from")
+    private String mailFrom;
+    @Column("rcpt_to")
+    private String rcptTo;
+    @Column("message")
+    private byte[] message;
+    @Column("status")
+    private String status = PENDING;
+    @Column("attempts")
+    private int attempts;
+    @Column("next_attempt_at")
+    private Instant nextAttemptAt;
+    @Column("last_error")
+    private String lastError;
+    @Column("created_at")
+    private Instant createdAt;
+    @Column("finished_at")
+    private Instant finishedAt;
+
+    public Long getId() { return id; }
+    public void setId(Long id) { this.id = id; }
+    public String getMailFrom() { return mailFrom; }
+    public void setMailFrom(String mailFrom) { this.mailFrom = mailFrom; }
+    public String getRcptTo() { return rcptTo; }
+    public void setRcptTo(String rcptTo) { this.rcptTo = rcptTo; }
+    public byte[] getMessage() { return message; }
+    public void setMessage(byte[] message) { this.message = message; }
+    public String getStatus() { return status; }
+    public void setStatus(String status) { this.status = status; }
+    public int getAttempts() { return attempts; }
+    public void setAttempts(int attempts) { this.attempts = attempts; }
+    public Instant getNextAttemptAt() { return nextAttemptAt; }
+    public void setNextAttemptAt(Instant nextAttemptAt) { this.nextAttemptAt = nextAttemptAt; }
+    public String getLastError() { return lastError; }
+    public void setLastError(String lastError) { this.lastError = lastError; }
+    public Instant getCreatedAt() { return createdAt; }
+    public void setCreatedAt(Instant createdAt) { this.createdAt = createdAt; }
+    public Instant getFinishedAt() { return finishedAt; }
+    public void setFinishedAt(Instant finishedAt) { this.finishedAt = finishedAt; }
+}

backend/src/main/java/com/mailserver/delivery/OutboundQueue.java

@@ -0,0 +1,28 @@
+package com.mailserver.delivery;
+
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+import java.time.Instant;
+
+/** Puts a message for one external recipient into the delivery queue (the worker sends it). */
+@Service
+public class OutboundQueue {
+
+    private final OutboundRepository repository;
+
+    public OutboundQueue(OutboundRepository repository) {
+        this.repository = repository;
+    }
+
+    public Mono<OutboundMessage> enqueue(String mailFrom, String rcptTo, byte[] signedMessage) {
+        OutboundMessage message = new OutboundMessage();
+        message.setMailFrom(mailFrom);
+        message.setRcptTo(rcptTo);
+        message.setMessage(signedMessage);
+        message.setStatus(OutboundMessage.PENDING);
+        message.setCreatedAt(Instant.now());
+        message.setNextAttemptAt(Instant.now());
+        return repository.save(message);
+    }
+}

backend/src/main/java/com/mailserver/delivery/OutboundRepository.java

@@ -0,0 +1,13 @@
+package com.mailserver.delivery;
+
+import org.springframework.data.r2dbc.repository.Query;
+import org.springframework.data.r2dbc.repository.R2dbcRepository;
+import reactor.core.publisher.Flux;
+
+import java.time.Instant;
+
+public interface OutboundRepository extends R2dbcRepository<OutboundMessage, Long> {
+
+    @Query("SELECT * FROM outbound_queue WHERE status = 'PENDING' AND next_attempt_at <= :now ORDER BY next_attempt_at LIMIT :limit")
+    Flux<OutboundMessage> findDue(Instant now, int limit);
+}

backend/src/main/java/com/mailserver/delivery/SmtpDeliveryClient.java

@@ -0,0 +1,244 @@
+package com.mailserver.delivery;
+
+import jakarta.mail.Address;
+import jakarta.mail.AuthenticationFailedException;
+import jakarta.mail.MessagingException;
+import jakarta.mail.SendFailedException;
+import jakarta.mail.Session;
+import jakarta.mail.Transport;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import org.eclipse.angus.mail.smtp.SMTPAddressFailedException;
+import org.eclipse.angus.mail.smtp.SMTPSendFailedException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.xbill.DNS.Lookup;
+import org.xbill.DNS.MXRecord;
+import org.xbill.DNS.Record;
+import org.xbill.DNS.TextParseException;
+import org.xbill.DNS.Type;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+import java.util.Properties;
+
+/**
+ * Delivers one message to one recipient over SMTP (Jakarta Mail), blocking.
+ * <ul>
+ *   <li><b>mx</b> — straight to the recipient's MX servers on port 25, lowest preference first; STARTTLS when offered,
+ *       without certificate checks — opportunistic, like Postfix {@code smtp_tls_security_level=may};</li>
+ *   <li><b>smarthost</b> — everything through one provider (Resend, SES, …) with login and verified TLS;</li>
+ *   <li><b>off</b> — nothing leaves the server.</li>
+ * </ul>
+ * The message bytes are sent exactly as given (they carry the DKIM signature).
+ */
+public class SmtpDeliveryClient {
+
+    private static final Logger log = LoggerFactory.getLogger(SmtpDeliveryClient.class);
+
+    public enum Mode { OFF, MX, SMARTHOST }
+
+    public enum Tls { NONE, STARTTLS, SSL }
+
+    /** port — of the smarthost; mxPort — of recipients' MX servers (25; another value only in tests). */
+    public record Settings(Mode mode, String host, int port, String username, String password, Tls tls,
+                           String heloName, int timeoutMs, int mxPort) {
+    }
+
+    public enum Outcome { DELIVERED, TEMPORARY, PERMANENT }
+
+    public record Result(Outcome outcome, String detail) {
+        static Result delivered(String detail) { return new Result(Outcome.DELIVERED, detail); }
+        static Result temporary(String detail) { return new Result(Outcome.TEMPORARY, detail); }
+        static Result permanent(String detail) { return new Result(Outcome.PERMANENT, detail); }
+    }
+
+    /** MX hosts of a domain, best first; empty — the domain has no mail server. */
+    public interface MxResolver {
+        List<String> resolve(String domain) throws TemporaryDnsException;
+    }
+
+    public static class TemporaryDnsException extends Exception {
+        public TemporaryDnsException(String message) {
+            super(message);
+        }
+    }
+
+    private final Settings settings;
+    private final MxResolver resolver;
+
+    public SmtpDeliveryClient(Settings settings) {
+        this(settings, SmtpDeliveryClient::dnsMx);
+    }
+
+    public SmtpDeliveryClient(Settings settings, MxResolver resolver) {
+        this.settings = settings;
+        this.resolver = resolver;
+    }
+
+    public Mode mode() {
+        return settings.mode();
+    }
+
+    public Result deliver(String from, String recipient, byte[] message) {
+        return switch (settings.mode()) {
+            case OFF -> Result.permanent("outbound delivery is disabled on this server");
+            case SMARTHOST -> send(settings.host(), settings.port(), true, from, recipient, message);
+            case MX -> viaMx(from, recipient, message);
+        };
+    }
+
+    private Result viaMx(String from, String recipient, byte[] message) {
+        String domain = recipient.substring(recipient.lastIndexOf('@') + 1).toLowerCase(Locale.ROOT);
+        List<String> hosts;
+        try {
+            hosts = resolver.resolve(domain);
+        } catch (TemporaryDnsException e) {
+            return Result.temporary("DNS: " + e.getMessage());
+        }
+        if (hosts.isEmpty()) {
+            return Result.permanent("domain " + domain + " does not accept mail (no MX/A record)");
+        }
+        Result last = null;
+        for (String host : hosts) {
+            last = send(host, settings.mxPort(), false, from, recipient, message);
+            // A server answered with a decision — do not ask the next MX; only a connection problem moves on
+            if (last.outcome() != Outcome.TEMPORARY || last.detail().startsWith("4")) {
+                return last;
+            }
+        }
+        return last;
+    }
+
+    private Result send(String host, int port, boolean smarthost, String from, String recipient, byte[] message) {
+        Properties props = new Properties();
+        props.put("mail.smtp.host", host);
+        props.put("mail.smtp.port", String.valueOf(port));
+        props.put("mail.smtp.localhost", settings.heloName());
+        props.put("mail.smtp.connectiontimeout", String.valueOf(settings.timeoutMs()));
+        props.put("mail.smtp.timeout", String.valueOf(settings.timeoutMs()));
+        props.put("mail.smtp.writetimeout", String.valueOf(settings.timeoutMs()));
+        props.put("mail.smtp.from", from);
+        props.put("mail.smtp.allow8bitmime", "true");
+        boolean login = false;
+        if (smarthost) {
+            switch (settings.tls()) {
+                case STARTTLS -> {
+                    props.put("mail.smtp.starttls.enable", "true");
+                    props.put("mail.smtp.starttls.required", "true");
+                }
+                case SSL -> props.put("mail.smtp.ssl.enable", "true");
+                case NONE -> { }
+            }
+            props.put("mail.smtp.ssl.checkserveridentity", "true");
+            login = settings.username() != null && !settings.username().isBlank();
+            props.put("mail.smtp.auth", String.valueOf(login));
+        } else {
+            props.put("mail.smtp.starttls.enable", "true");
+            props.put("mail.smtp.ssl.trust", "*");
+        }
+        Session session = Session.getInstance(props);
+        try (Transport transport = session.getTransport(settings.tls() == Tls.SSL && smarthost ? "smtps" : "smtp")) {
+            if (login) {
+                transport.connect(host, port, settings.username(), settings.password());
+            } else {
+                transport.connect(host, port, null, null);
+            }
+            transport.sendMessage(new RawMessage(session, message), new Address[]{new InternetAddress(recipient)});
+            log.info("Delivered {} -> {} via {}:{}", from, recipient, host, port);
+            return Result.delivered(host);
+        } catch (AuthenticationFailedException e) {
+            return Result.temporary("login to " + host + " failed: " + e.getMessage());
+        } catch (MessagingException e) {
+            int code = replyCode(e);
+            String text = code > 0 ? code + " " + oneLine(e) : "connection to " + host + ": " + oneLine(e);
+            log.warn("Delivery {} -> {} via {}: {}", from, recipient, host, text);
+            return code >= 500 ? Result.permanent(text) : Result.temporary(text);
+        }
+    }
+
+    /** SMTP reply code from the exception chain, 0 — no reply (connection problem). */
+    static int replyCode(Exception e) {
+        Exception current = e;
+        while (current != null) {
+            if (current instanceof SMTPAddressFailedException f) {
+                return f.getReturnCode();
+            }
+            if (current instanceof SMTPSendFailedException f) {
+                return f.getReturnCode();
+            }
+            current = current instanceof MessagingException m ? m.getNextException()
+                    : current.getCause() instanceof Exception c ? c : null;
+            if (current instanceof SendFailedException sf && sf.getInvalidAddresses() != null
+                    && sf.getNextException() == null) {
+                return 550;
+            }
+        }
+        return 0;
+    }
+
+    private static String oneLine(Exception e) {
+        String message = String.valueOf(e.getMessage()).replaceAll("\\s+", " ").trim();
+        return message.length() > 500 ? message.substring(0, 500) : message;
+    }
+
+    /** MX hosts by preference (RFC 5321 5.1); no MX — the domain itself (implicit MX); null MX "." — none. */
+    static List<String> dnsMx(String domain) throws TemporaryDnsException {
+        try {
+            Lookup lookup = new Lookup(domain, Type.MX);
+            Record[] records = lookup.run();
+            switch (lookup.getResult()) {
+                case Lookup.SUCCESSFUL -> {
+                    List<String> hosts = Arrays.stream(records)
+                            .map(MXRecord.class::cast)
+                            .sorted(Comparator.comparingInt(MXRecord::getPriority))
+                            .map(mx -> mx.getTarget().toString(true))
+                            .filter(host -> !host.isEmpty() && !host.equals("."))
+                            .toList();
+                    return hosts;
+                }
+                case Lookup.TYPE_NOT_FOUND -> {
+                    Lookup a = new Lookup(domain, Type.A);
+                    a.run();
+                    return a.getResult() == Lookup.SUCCESSFUL ? List.of(domain) : List.of();
+                }
+                case Lookup.HOST_NOT_FOUND -> {
+                    return List.of();
+                }
+                default -> throw new TemporaryDnsException(lookup.getErrorString());
+            }
+        } catch (TextParseException e) {
+            return List.of();
+        }
+    }
+
+    /** A message written to the wire byte for byte as received (keeps the DKIM signature valid). */
+    static final class RawMessage extends MimeMessage {
+        private final byte[] raw;
+
+        RawMessage(Session session, byte[] raw) throws MessagingException {
+            super(session, new ByteArrayInputStream(raw));
+            this.raw = raw;
+        }
+
+        @Override
+        public void writeTo(OutputStream os, String[] ignoreHeaders) throws IOException {
+            os.write(raw);
+        }
+
+        @Override
+        public void writeTo(OutputStream os) throws IOException {
+            os.write(raw);
+        }
+
+        @Override
+        public int getSize() {
+            return raw.length;
+        }
+    }
+}

backend/src/main/java/com/mailserver/dev/DevController.java

@@ -0,0 +1,31 @@
+package com.mailserver.dev;
+
+import com.mailserver.service.MailService;
+import org.springframework.context.annotation.Profile;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+import reactor.core.publisher.Mono;
+
+import java.util.Map;
+
+/** Dev profile only: put a message into a mailbox without SMTP (any sender — never on a real server). */
+@RestController
+@Profile("dev")
+public class DevController {
+
+    private final MailService mailService;
+
+    public DevController(MailService mailService) {
+        this.mailService = mailService;
+    }
+
+    @PostMapping("/api/simulate/receive")
+    public Mono<ResponseEntity<Map<String, String>>> simulateReceive(@RequestBody Map<String, String> body) {
+        return mailService.receiveMessage(body.get("senderEmail"), body.get("senderName"), body.get("recipientEmail"),
+                        body.getOrDefault("subject", ""), body.getOrDefault("body", ""), "true".equals(body.get("html")))
+                .thenReturn(ResponseEntity.ok(Map.of("message", "Message received")))
+                .onErrorResume(e -> Mono.just(ResponseEntity.badRequest().body(Map.of("error", String.valueOf(e.getMessage())))));
+    }
+}

backend/src/main/java/com/mailserver/domain/Folder.java

@@ -24,6 +24,9 @@ public class Folder {
     @Column("unread_count")
     private Integer unreadCount = 0;
 
+    @Column("is_system")
+    private boolean system;
+
     @Column("created_at")
     private Instant createdAt;
 
@@ -42,6 +45,9 @@ public class Folder {
     public Integer getUnreadCount() { return unreadCount; }
     public void setUnreadCount(Integer unreadCount) { this.unreadCount = unreadCount; }
 
+    public boolean isSystem() { return system; }
+    public void setSystem(boolean system) { this.system = system; }
+
     public Instant getCreatedAt() { return createdAt; }
     public void setCreatedAt(Instant createdAt) { this.createdAt = createdAt; }
 }

backend/src/main/java/com/mailserver/domain/Message.java

@@ -24,6 +24,9 @@ public class Message {
     @Column("recipient_email")
     private String recipientEmail;
 
+    @Column("cc_email")
+    private String ccEmail;
+
     @Column("subject")
     private String subject;
 
@@ -66,6 +69,9 @@ public class Message {
     public String getRecipientEmail() { return recipientEmail; }
     public void setRecipientEmail(String recipientEmail) { this.recipientEmail = recipientEmail; }
 
+    public String getCcEmail() { return ccEmail; }
+    public void setCcEmail(String ccEmail) { this.ccEmail = ccEmail; }
+
     public String getSubject() { return subject; }
     public void setSubject(String subject) { this.subject = subject; }
 

backend/src/main/java/com/mailserver/dto/DraftRequest.java

@@ -0,0 +1,8 @@
+package com.mailserver.dto;
+
+import jakarta.validation.constraints.Size;
+
+/** A draft: everything optional, addresses are not checked until it is sent. */
+public record DraftRequest(@Size(max = 5000) String to, @Size(max = 5000) String cc,
+                           @Size(max = 1000) String subject, @Size(max = 1_000_000) String body, boolean html) {
+}

backend/src/main/java/com/mailserver/dto/FolderRequest.java

@@ -0,0 +1,7 @@
+package com.mailserver.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record FolderRequest(@NotBlank @Size(max = 50) String name) {
+}

backend/src/main/java/com/mailserver/dto/FolderResponse.java

@@ -1,23 +1,5 @@
 package com.mailserver.dto;
 
-import java.time.Instant;
+/** A folder with live counters; system = INBOX, Drafts, Sent, Spam, Trash (cannot be renamed or deleted). */
-
+public record FolderResponse(Long id, String name, boolean system, long messageCount, long unreadCount) {
-public class FolderResponse {
-
-    private Long id;
-    private String name;
-    private Integer messageCount;
-    private Integer unreadCount;
-
-    public Long getId() { return id; }
-    public void setId(Long id) { this.id = id; }
-
-    public String getName() { return name; }
-    public void setName(String name) { this.name = name; }
-
-    public Integer getMessageCount() { return messageCount; }
-    public void setMessageCount(Integer messageCount) { this.messageCount = messageCount; }
-
-    public Integer getUnreadCount() { return unreadCount; }
-    public void setUnreadCount(Integer unreadCount) { this.unreadCount = unreadCount; }
 }

backend/src/main/java/com/mailserver/dto/MessageResponse.java

@@ -8,6 +8,7 @@ public class MessageResponse {
     private String senderEmail;
     private String senderName;
     private String recipientEmail;
+    private String ccEmail;
     private String subject;
     private String body;
     private boolean html;
@@ -32,6 +33,9 @@ public class MessageResponse {
     public String getRecipientEmail() { return recipientEmail; }
     public void setRecipientEmail(String recipientEmail) { this.recipientEmail = recipientEmail; }
 
+    public String getCcEmail() { return ccEmail; }
+    public void setCcEmail(String ccEmail) { this.ccEmail = ccEmail; }
+
     public String getSubject() { return subject; }
     public void setSubject(String subject) { this.subject = subject; }
 

backend/src/main/java/com/mailserver/dto/MessageUpdateRequest.java

@@ -0,0 +1,5 @@
+package com.mailserver.dto;
+
+/** Partial update of a message: only the fields that are set change. */
+public record MessageUpdateRequest(Boolean read, Boolean flagged, Long folderId) {
+}

backend/src/main/java/com/mailserver/dto/PasswordChangeRequest.java

@@ -0,0 +1,7 @@
+package com.mailserver.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record PasswordChangeRequest(@NotBlank String currentPassword, @NotBlank @Size(min = 8, max = 100) String newPassword) {
+}

backend/src/main/java/com/mailserver/dto/ProfileResponse.java

@@ -0,0 +1,8 @@
+package com.mailserver.dto;
+
+import java.time.Instant;
+
+/** @param admin may manage mailboxes ({@link com.mailserver.config.MailAdmins}) */
+public record ProfileResponse(String email, String displayName, long usedBytes, long quotaBytes, Instant createdAt,
+                              boolean admin) {
+}

backend/src/main/java/com/mailserver/dto/ProfileUpdateRequest.java

@@ -0,0 +1,7 @@
+package com.mailserver.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record ProfileUpdateRequest(@NotBlank @Size(max = 100) String displayName) {
+}

backend/src/main/java/com/mailserver/dto/RegisterRequest.java

@@ -12,7 +12,7 @@ public class RegisterRequest {
     private String email;
 
     @NotBlank
-    @Size(min = 6, max = 100)
+    @Size(min = 8, max = 100)
     private String password;
 
     @Size(max = 100)

backend/src/main/java/com/mailserver/dto/SendRequest.java

@@ -1,31 +1,46 @@
 package com.mailserver.dto;
 
-import jakarta.validation.constraints.Email;
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
 
+/**
+ * "Send" from the web client. {@code to} and {@code cc}: one or more addresses separated by commas, semicolons or
+ * spaces. {@code draftId}: the draft being sent — its attachments go with the message, the draft is removed.
+ */
 public class SendRequest {
 
     @NotBlank
-    @Email
+    @Size(max = 5000)
     private String to;
 
-    @NotBlank
+    @Size(max = 5000)
+    private String cc;
+
+    @Size(max = 1000)
     private String subject;
 
-    @NotBlank
+    @Size(max = 1_000_000)
     private String body;
 
     private boolean html = false;
 
+    private Long draftId;
+
     public String getTo() { return to; }
     public void setTo(String to) { this.to = to; }
 
-    public String getSubject() { return subject; }
+    public String getCc() { return cc; }
+    public void setCc(String cc) { this.cc = cc; }
+
+    public String getSubject() { return subject == null ? "" : subject; }
     public void setSubject(String subject) { this.subject = subject; }
 
-    public String getBody() { return body; }
+    public String getBody() { return body == null ? "" : body; }
     public void setBody(String body) { this.body = body; }
 
     public boolean isHtml() { return html; }
     public void setHtml(boolean html) { this.html = html; }
+
+    public Long getDraftId() { return draftId; }
+    public void setDraftId(Long draftId) { this.draftId = draftId; }
 }

backend/src/main/java/com/mailserver/imap/DbImapStore.java

@@ -0,0 +1,285 @@
+package com.mailserver.imap;
+
+import com.mailserver.domain.Attachment;
+import com.mailserver.domain.Message;
+import com.mailserver.domain.User;
+import com.mailserver.repository.AttachmentRepository;
+import com.mailserver.repository.MessageRepository;
+import com.mailserver.repository.UserRepository;
+import com.mailserver.service.LocalDelivery;
+import com.mailserver.service.MailService;
+import com.mailserver.service.MessageSources;
+import com.mailserver.service.UserService;
+import jakarta.mail.Session;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.r2dbc.core.DatabaseClient;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.Properties;
+import java.util.UUID;
+
+/** {@link ImapStore} over the mail server's PostgreSQL tables (the same data the web client shows). */
+public class DbImapStore implements ImapStore {
+
+    private static final Logger log = LoggerFactory.getLogger(DbImapStore.class);
+
+    private final DatabaseClient db;
+    private final UserRepository users;
+    private final UserService userService;
+    private final MailService mailService;
+    private final MessageRepository messages;
+    private final AttachmentRepository attachments;
+    private final MessageSources sources;
+    private final String hostname;
+
+    public DbImapStore(DatabaseClient db, UserRepository users, UserService userService, MailService mailService,
+                       MessageRepository messages, AttachmentRepository attachments, MessageSources sources,
+                       String hostname) {
+        this.db = db;
+        this.users = users;
+        this.userService = userService;
+        this.mailService = mailService;
+        this.messages = messages;
+        this.attachments = attachments;
+        this.sources = sources;
+        this.hostname = hostname;
+    }
+
+    @Override
+    public Account authenticate(String username, String password) {
+        User user = users.findByEmail(username.trim().toLowerCase(Locale.ROOT)).block();
+        if (user == null || !user.isActive() || !userService.checkPassword(user, password)) {
+            return null;
+        }
+        return new Account(user.getId(), user.getEmail());
+    }
+
+    @Override
+    public List<Mailbox> mailboxes(long userId) {
+        return db.sql("SELECT id, name, is_system, uid_validity, uid_next FROM folders WHERE user_id = :u ORDER BY id")
+                .bind("u", userId)
+                .map(row -> new Mailbox(row.get("id", Long.class), row.get("name", String.class),
+                        Boolean.TRUE.equals(row.get("is_system", Boolean.class)),
+                        row.get("uid_validity", Long.class), row.get("uid_next", Long.class)))
+                .all().collectList().block();
+    }
+
+    @Override
+    public Mailbox create(long userId, String name) {
+        try {
+            var created = mailService.createFolder(userId, name).block();
+            return mailboxes(userId).stream().filter(m -> m.id() == created.id()).findFirst().orElseThrow();
+        } catch (ResponseStatusException e) {
+            throw new Refused(e.getReason());
+        }
+    }
+
+    @Override
+    public void rename(long userId, Mailbox mailbox, String newName) {
+        try {
+            mailService.renameFolder(mailbox.id(), userId, newName).block();
+        } catch (ResponseStatusException e) {
+            throw new Refused(e.getReason());
+        }
+    }
+
+    @Override
+    public void delete(long userId, Mailbox mailbox) {
+        try {
+            mailService.deleteFolder(mailbox.id(), userId).block();
+        } catch (ResponseStatusException e) {
+            throw new Refused(e.getReason());
+        }
+    }
+
+    @Override
+    public List<Entry> entries(long folderId) {
+        return db.sql("SELECT id, uid, is_read, is_flagged, is_answered, is_deleted, received_at FROM messages "
+                        + "WHERE folder_id = :f ORDER BY uid")
+                .bind("f", folderId)
+                .map(row -> new Entry(row.get("id", Long.class), row.get("uid", Long.class),
+                        Boolean.TRUE.equals(row.get("is_read", Boolean.class)),
+                        Boolean.TRUE.equals(row.get("is_flagged", Boolean.class)),
+                        Boolean.TRUE.equals(row.get("is_answered", Boolean.class)),
+                        Boolean.TRUE.equals(row.get("is_deleted", Boolean.class)),
+                        instant(row.get("received_at"))))
+                .all().collectList().block();
+    }
+
+    @Override
+    public byte[] source(long messageId) {
+        byte[] raw = sources.get(messageId).block();
+        if (raw != null) {
+            return raw;
+        }
+        Message message = messages.findById(messageId).block();
+        if (message == null) {
+            return new byte[0];
+        }
+        try {
+            List<Attachment> files = attachments.findByMessageId(messageId).collectList().block();
+            raw = MimeSource.build(message, files, hostname);
+        } catch (Exception e) {
+            log.warn("IMAP: cannot build message {}: {}", messageId, e.toString());
+            return ("Subject: " + message.getSubject() + "\r\n\r\n" + message.getBody()).getBytes();
+        }
+        sources.put(messageId, raw).block();
+        return raw;
+    }
+
+    @Override
+    public void setFlags(long messageId, boolean seen, boolean flagged, boolean answered, boolean deleted) {
+        db.sql("UPDATE messages SET is_read = :s, is_flagged = :f, is_answered = :a, is_deleted = :d WHERE id = :id")
+                .bind("s", seen).bind("f", flagged).bind("a", answered).bind("d", deleted).bind("id", messageId)
+                .then().block();
+    }
+
+    @Override
+    public long append(long userId, Mailbox target, byte[] raw, boolean seen, boolean flagged, boolean answered,
+                       boolean deleted, Instant internalDate) {
+        try {
+            MimeMessage mime = new MimeMessage(Session.getInstance(new Properties()), new ByteArrayInputStream(raw));
+            Message message = new Message();
+            message.setFolderId(target.id());
+            String senderEmail = "unknown@" + hostname;
+            String senderName = null;
+            if (mime.getFrom() != null && mime.getFrom().length > 0 && mime.getFrom()[0] instanceof InternetAddress from) {
+                senderEmail = from.getAddress();
+                senderName = from.getPersonal();
+            }
+            message.setSenderEmail(senderEmail);
+            message.setSenderName(senderName);
+            String to = LocalDelivery.addresses(mime, jakarta.mail.Message.RecipientType.TO);
+            message.setRecipientEmail(to == null ? "" : to);
+            message.setCcEmail(LocalDelivery.addresses(mime, jakarta.mail.Message.RecipientType.CC));
+            message.setSubject(mime.getSubject() == null ? "" : mime.getSubject());
+            LocalDelivery.Body body = LocalDelivery.body(mime);
+            message.setBody(body.text());
+            message.setHtml(body.html());
+            message.setRead(seen);
+            message.setFlagged(flagged);
+            message.setSpam(target.system() && "Spam".equals(target.name()));
+            message.setReceivedAt(internalDate == null ? Instant.now() : internalDate);
+            String messageId = mime.getMessageID();
+            message.setMessageId(messageId == null ? UUID.randomUUID().toString() : messageId.replaceAll("^<|>$", ""));
+            message.setMessageSize((long) raw.length);
+            Message stored = messages.save(message).block();
+            for (LocalDelivery.FilePart file : LocalDelivery.attachments(mime)) {
+                mailService.storeIncomingAttachment(stored.getId(), file.name(), file.contentType(), file.bytes());
+            }
+            sources.put(stored.getId(), raw).block();
+            setFlags(stored.getId(), seen, flagged, answered, deleted);
+            return uid(stored.getId());
+        } catch (Refused e) {
+            throw e;
+        } catch (Exception e) {
+            log.warn("IMAP APPEND to {} failed: {}", target.name(), e.toString());
+            throw new Refused("Cannot store the message: " + e.getMessage());
+        }
+    }
+
+    @Override
+    public List<Long> copy(long userId, List<Entry> list, Mailbox target) {
+        boolean spam = target.system() && "Spam".equals(target.name());
+        List<Long> uids = new ArrayList<>();
+        for (Entry entry : list) {
+            Long newId = db.sql("INSERT INTO messages (folder_id, sender_email, sender_name, recipient_email, cc_email, "
+                            + "subject, body, is_html, is_read, is_flagged, is_spam, is_answered, is_deleted, message_size, "
+                            + "received_at, message_id) "
+                            + "SELECT :t, sender_email, sender_name, recipient_email, cc_email, subject, body, is_html, "
+                            + "is_read, is_flagged, :spam, is_answered, is_deleted, message_size, received_at, message_id "
+                            + "FROM messages WHERE id = :id RETURNING id")
+                    .bind("t", target.id()).bind("spam", spam).bind("id", entry.id())
+                    .map(row -> row.get("id", Long.class)).one().block();
+            if (newId == null) {
+                continue;
+            }
+            for (Attachment attachment : attachments.findByMessageId(entry.id()).collectList().block()) {
+                copyAttachment(attachment, newId);
+            }
+            db.sql("INSERT INTO message_sources (message_id, raw) SELECT :n, raw FROM message_sources WHERE message_id = :o")
+                    .bind("n", newId).bind("o", entry.id()).then().block();
+            uids.add(uid(newId));
+        }
+        return uids;
+    }
+
+    private void copyAttachment(Attachment attachment, long newMessageId) {
+        try {
+            Path from = Paths.get(attachment.getFilePath());
+            Path to = from.resolveSibling(UUID.randomUUID() + "_" + from.getFileName().toString().replaceFirst("^[0-9a-f-]{36}_", ""));
+            Files.copy(from, to);
+            Attachment copy = new Attachment();
+            copy.setMessageId(newMessageId);
+            copy.setFilename(attachment.getFilename());
+            copy.setContentType(attachment.getContentType());
+            copy.setSizeBytes(attachment.getSizeBytes());
+            copy.setFilePath(to.toString());
+            copy.setContentId(attachment.getContentId());
+            attachments.save(copy).block();
+        } catch (IOException e) {
+            log.warn("IMAP COPY: attachment {} not copied: {}", attachment.getFilePath(), e.toString());
+        }
+    }
+
+    @Override
+    public List<Long> move(long userId, List<Entry> list, Mailbox target) {
+        boolean spam = target.system() && "Spam".equals(target.name());
+        List<Long> uids = new ArrayList<>();
+        for (Entry entry : list) {
+            Long uid = db.sql("UPDATE messages SET folder_id = :t, is_spam = :spam WHERE id = :id RETURNING uid")
+                    .bind("t", target.id()).bind("spam", spam).bind("id", entry.id())
+                    .map(row -> row.get("uid", Long.class)).one().block();
+            if (uid != null) {
+                uids.add(uid);
+            }
+        }
+        return uids;
+    }
+
+    @Override
+    public void expunge(List<Long> messageIds) {
+        for (Long id : messageIds) {
+            for (Attachment attachment : attachments.findByMessageId(id).collectList().block()) {
+                try {
+                    Files.deleteIfExists(Paths.get(attachment.getFilePath()));
+                } catch (IOException e) {
+                    log.warn("Attachment file {} not deleted: {}", attachment.getFilePath(), e.getMessage());
+                }
+            }
+            messages.deleteById(id).block();
+        }
+    }
+
+    private long uid(long messageId) {
+        return db.sql("SELECT uid FROM messages WHERE id = :id").bind("id", messageId)
+                .map(row -> row.get("uid", Long.class)).one().block();
+    }
+
+    private static Instant instant(Object value) {
+        if (value instanceof Instant instant) {
+            return instant;
+        }
+        if (value instanceof LocalDateTime local) {
+            return local.toInstant(ZoneOffset.UTC);
+        }
+        if (value instanceof java.time.OffsetDateTime offset) {
+            return offset.toInstant();
+        }
+        return Instant.EPOCH;
+    }
+}

backend/src/main/java/com/mailserver/imap/ImapReader.java

@@ -0,0 +1,194 @@
+package com.mailserver.imap;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Reads one IMAP command: the decoder has already collected it whole, with its literals inline
+ * ("{n}\r\n" + n bytes, or "{n+}\r\n" + n bytes).
+ */
+final class ImapReader {
+
+    static final class SyntaxError extends RuntimeException {
+        SyntaxError(String message) {
+            super(message);
+        }
+    }
+
+    private final byte[] b;
+    private int pos;
+
+    ImapReader(byte[] command) {
+        this(command, true);
+    }
+
+    private ImapReader(byte[] command, boolean stripLineEnd) {
+        int end = command.length;
+        if (!stripLineEnd) {
+            this.b = command;
+            return;
+        }
+        if (end > 0 && command[end - 1] == '\n') {
+            end--;
+        }
+        if (end > 0 && command[end - 1] == '\r') {
+            end--;
+        }
+        this.b = java.util.Arrays.copyOf(command, end);
+    }
+
+    boolean atEnd() {
+        return pos >= b.length;
+    }
+
+    int peek() {
+        return pos < b.length ? b[pos] & 0xff : -1;
+    }
+
+    void sp() {
+        if (peek() != ' ') {
+            throw new SyntaxError("Expected a space");
+        }
+        while (peek() == ' ') {
+            pos++;
+        }
+    }
+
+    boolean optionalSp() {
+        if (peek() == ' ') {
+            sp();
+            return true;
+        }
+        return false;
+    }
+
+    void expect(char c) {
+        if (peek() != c) {
+            throw new SyntaxError("Expected '" + c + "'");
+        }
+        pos++;
+    }
+
+    /** Characters up to a space, parenthesis, or the end (an atom; also tags, sequence sets, flags). */
+    String atom() {
+        int start = pos;
+        while (pos < b.length) {
+            int c = b[pos] & 0xff;
+            if (c == ' ' || c == '(' || c == ')' || c == '{' || c == '"' || c < 0x20 || c == 0x7f) {
+                break;
+            }
+            pos++;
+        }
+        if (pos == start) {
+            throw new SyntaxError("Expected an atom");
+        }
+        return new String(b, start, pos - start, StandardCharsets.UTF_8);
+    }
+
+    /** Atom, quoted string or literal. */
+    String astring() {
+        int c = peek();
+        if (c == '"' || c == '{') {
+            return new String(stringBytes(), StandardCharsets.UTF_8);
+        }
+        return atom();
+    }
+
+    /** Quoted string or literal, raw bytes. */
+    byte[] stringBytes() {
+        int c = peek();
+        if (c == '"') {
+            pos++;
+            java.io.ByteArrayOutputStream out = new java.io.ByteArrayOutputStream();
+            while (true) {
+                if (pos >= b.length) {
+                    throw new SyntaxError("Unterminated quoted string");
+                }
+                byte x = b[pos++];
+                if (x == '"') {
+                    return out.toByteArray();
+                }
+                if (x == '\\' && pos < b.length) {
+                    x = b[pos++];
+                }
+                out.write(x);
+            }
+        }
+        if (c == '{') {
+            int close = indexOf('}', pos);
+            if (close < 0) {
+                throw new SyntaxError("Bad literal");
+            }
+            String size = new String(b, pos + 1, close - pos - 1, StandardCharsets.US_ASCII);
+            if (size.endsWith("+")) {
+                size = size.substring(0, size.length() - 1);
+            }
+            int length;
+            try {
+                length = Integer.parseInt(size);
+            } catch (NumberFormatException e) {
+                throw new SyntaxError("Bad literal size");
+            }
+            pos = close + 1;
+            if (peek() == '\r') {
+                pos++;
+            }
+            expect('\n');
+            if (pos + length > b.length) {
+                throw new SyntaxError("Literal shorter than announced");
+            }
+            byte[] data = java.util.Arrays.copyOfRange(b, pos, pos + length);
+            pos += length;
+            return data;
+        }
+        throw new SyntaxError("Expected a string");
+    }
+
+    /** "(a b c)" → [a, b, c] (atoms or strings); an atom without parentheses → [atom]. */
+    List<String> list() {
+        List<String> items = new ArrayList<>();
+        if (peek() != '(') {
+            items.add(astring());
+            return items;
+        }
+        pos++;
+        while (peek() == ' ') {
+            pos++;
+        }
+        while (peek() != ')') {
+            if (atEnd()) {
+                throw new SyntaxError("Unterminated list");
+            }
+            items.add(astring());
+            while (peek() == ' ') {
+                pos++;
+            }
+        }
+        pos++;
+        return items;
+    }
+
+    /** Everything left, as text (used for FETCH attributes and SEARCH keys parsed by their own readers). */
+    String rest() {
+        String text = new String(b, pos, b.length - pos, StandardCharsets.UTF_8);
+        pos = b.length;
+        return text;
+    }
+
+    /** A reader over the rest, as is (SEARCH may hold literals). */
+    ImapReader restReader() {
+        ImapReader reader = new ImapReader(java.util.Arrays.copyOfRange(b, pos, b.length), false);
+        pos = b.length;
+        return reader;
+    }
+
+    private int indexOf(char c, int from) {
+        for (int i = from; i < b.length; i++) {
+            if (b[i] == c) {
+                return i;
+            }
+        }
+        return -1;
+    }
+}

backend/src/main/java/com/mailserver/imap/ImapServer.java

@@ -0,0 +1,273 @@
+package com.mailserver.imap;
+
+import com.mailserver.security.LoginGuard;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.handler.codec.TooLongFrameException;
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.SslHandler;
+import io.netty.handler.timeout.ReadTimeoutHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.publisher.Sinks;
+import reactor.core.scheduler.Schedulers;
+import reactor.netty.Connection;
+import reactor.netty.DisposableServer;
+import reactor.netty.NettyOutbound;
+import reactor.netty.tcp.TcpServer;
+
+import java.io.ByteArrayOutputStream;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.util.List;
+import java.util.Locale;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * IMAP server (RFC 3501) on Reactor Netty.
+ * <ul>
+ *   <li>{@link CommandDecoder} collects whole commands with their literals ({n} — after "+ Ready", {n+} — at once);</li>
+ *   <li>each command runs on a worker thread (database, MIME parsing), never on the event loop; responses are written
+ *       in order, one command at a time;</li>
+ *   <li>TLS: STARTTLS, or implicit TLS on a separate port (993); LOGIN/AUTHENTICATE only inside TLS unless
+ *       {@code authWithoutTls}; plain text sent together with STARTTLS is never executed;</li>
+ *   <li>IDLE: changes of the selected mailbox are pushed every {@code idlePoll} until DONE.</li>
+ * </ul>
+ */
+public class ImapServer {
+
+    private static final Logger log = LoggerFactory.getLogger(ImapServer.class);
+
+    static final int MAX_LINE = 64 * 1024;
+    private static final int MAX_QUEUED = 1000;
+    private static final Pattern LITERAL = Pattern.compile("\\{(\\d+)(\\+?)}\r?\n$");
+    private static final Pattern IDLE = Pattern.compile("^(\\S+) IDLE\\s*$", Pattern.CASE_INSENSITIVE);
+    private static final Duration IDLE_MAX = Duration.ofMinutes(29);
+
+    /**
+     * @param tls            certificate; null — no TLS
+     * @param implicitTls    TLS from the first byte (port 993)
+     * @param maxLiteral     the largest literal accepted (APPEND of a big message)
+     * @param idlePoll       how often IDLE looks for changes
+     */
+    public record Settings(String host, int port, String hostname, boolean authWithoutTls, SslContext tls,
+                           boolean implicitTls, int maxLiteral, Duration idleTimeout, Duration idlePoll) {
+    }
+
+    /** A whole command and whether it arrived over TLS. */
+    record Command(byte[] bytes, boolean tls) {
+    }
+
+    private final Settings settings;
+    private final ImapStore store;
+    private final LoginGuard guard;
+    private DisposableServer server;
+
+    public ImapServer(Settings settings, ImapStore store) {
+        this(settings, store, LoginGuard.disabled());
+    }
+
+    public ImapServer(Settings settings, ImapStore store, LoginGuard guard) {
+        this.settings = settings;
+        this.store = store;
+        this.guard = guard;
+    }
+
+    public void start() {
+        if (settings.implicitTls() && settings.tls() == null) {
+            throw new IllegalStateException("Implicit TLS needs a certificate");
+        }
+        TcpServer tcp = TcpServer.create()
+                .host(settings.host())
+                .port(settings.port())
+                .doOnConnection(connection -> connection
+                        .addHandlerFirst("imap-idle", new ReadTimeoutHandler(settings.idleTimeout().toSeconds(), TimeUnit.SECONDS))
+                        .addHandlerLast("imap-commands", new CommandDecoder(settings.maxLiteral())));
+        if (settings.implicitTls()) {
+            tcp = tcp.secure(spec -> spec.sslContext(settings.tls()));
+        }
+        server = tcp.handle((inbound, outbound) -> {
+                    Connection[] connection = {null};
+                    String[] remoteIp = {"unknown"};
+                    inbound.withConnection(c -> {
+                        connection[0] = c;
+                        if (c.address() instanceof InetSocketAddress address && address.getAddress() != null) {
+                            remoteIp[0] = address.getAddress().getHostAddress();
+                        }
+                    });
+                    ImapSession session = new ImapSession(
+                            new ImapSession.Settings(settings.hostname(), settings.tls() != null, settings.authWithoutTls()),
+                            store, guard, remoteIp[0], settings.implicitTls());
+                    @SuppressWarnings("unchecked")
+                    Sinks.Empty<Void>[] idleDone = new Sinks.Empty[1];
+
+                    Flux<byte[]> responses = inbound.receiveObject().cast(Command.class)
+                            // DONE ends IDLE while the IDLE command is still running — handled before the queue
+                            .filter(command -> {
+                                if (session.idling() && isDone(command.bytes())) {
+                                    if (idleDone[0] != null) {
+                                        idleDone[0].tryEmitEmpty();
+                                    }
+                                    return false;
+                                }
+                                return true;
+                            })
+                            // read commands as they come (so DONE is seen during IDLE), run them one by one
+                            .onBackpressureBuffer(MAX_QUEUED, dropped -> log.warn("IMAP {}: too many queued commands", session.remoteIp))
+                            .concatMap(command -> {
+                                if (session.tls && !command.tls()) {
+                                    // plain text sent together with STARTTLS: never executed, the connection is closed
+                                    log.warn("IMAP {}: plain-text command after STARTTLS, closing", session.remoteIp);
+                                    session.closing = true;
+                                    connection[0].dispose();
+                                    return Flux.empty();
+                                }
+                                String text = new String(command.bytes(), StandardCharsets.UTF_8).trim();
+                                Matcher idle = IDLE.matcher(text);
+                                if (idle.matches()) {
+                                    idleDone[0] = Sinks.empty();
+                                    return idle(session, idle.group(1), idleDone[0]);
+                                }
+                                return blocking(() -> session.handle(command.bytes()));
+                            })
+                            .onErrorResume(e -> {
+                                log.debug("IMAP {}: connection closed: {}", session.remoteIp, e.toString());
+                                return Mono.just(ImapSession.line("* BYE " + e.getMessage()));
+                            })
+                            // after the tagged line of the command that closes (LOGOUT, too many failed logins), not after
+                            // its first untagged "* BYE" — the tagged answer must still reach the client
+                            .takeUntil(response -> session.closing && !untagged(response));
+
+                    return Flux.concat(Mono.just(session.greeting()), responses)
+                            .concatMap(response -> response == ImapSession.STARTTLS_READY
+                                    ? startTls(connection[0], session)
+                                    : send(outbound, response))
+                            .then();
+                })
+                .bindNow(Duration.ofSeconds(10));
+        log.info("IMAP server listening on {}:{} ({}{})", settings.host(), port(), settings.hostname(),
+                settings.implicitTls() ? ", implicit TLS" : settings.tls() != null ? ", STARTTLS" : ", no TLS");
+    }
+
+    private Flux<byte[]> idle(ImapSession session, String tag, Sinks.Empty<Void> done) {
+        Flux<byte[]> polls = Flux.interval(settings.idlePoll())
+                .onBackpressureDrop()
+                .concatMap(tick -> blocking(session::idlePoll))
+                .takeUntilOther(done.asMono())
+                .take(IDLE_MAX);
+        return Flux.concat(
+                blocking(() -> session.idleStart(tag)),
+                Flux.defer(() -> session.idling() ? polls : Flux.empty()),
+                blocking(session::idleEnd));
+    }
+
+    private static boolean isDone(byte[] bytes) {
+        return new String(bytes, StandardCharsets.US_ASCII).trim().toUpperCase(Locale.ROOT).equals("DONE");
+    }
+
+    private static boolean untagged(byte[] response) {
+        return response.length > 1 && response[0] == '*' && response[1] == ' ';
+    }
+
+    private static Flux<byte[]> blocking(java.util.concurrent.Callable<List<byte[]>> work) {
+        return Mono.fromCallable(work).subscribeOn(Schedulers.boundedElastic()).flatMapIterable(list -> list);
+    }
+
+    private static Mono<Void> send(NettyOutbound outbound, byte[] response) {
+        return outbound.send(Mono.just(Unpooled.wrappedBuffer(response))).then();
+    }
+
+    /** After the tagged OK of STARTTLS has left in plain text: TLS in front, a fresh decoder (no plain leftovers). */
+    private Mono<Void> startTls(Connection connection, ImapSession session) {
+        ChannelPipeline pipeline = connection.channel().pipeline();
+        SslHandler ssl = settings.tls().newHandler(connection.channel().alloc());
+        pipeline.replace("imap-commands", "imap-commands", new CommandDecoder(settings.maxLiteral()));
+        pipeline.addFirst("imap-tls", ssl);
+        return Mono.create(sink -> ssl.handshakeFuture().addListener(future -> {
+            if (!future.isSuccess()) {
+                log.info("IMAP {}: TLS handshake failed: {}", session.remoteIp, future.cause().toString());
+                session.closing = true;
+                connection.dispose();
+            }
+            sink.success();
+        }));
+    }
+
+    public int port() {
+        return server.port();
+    }
+
+    public void stop() {
+        if (server != null) {
+            server.disposeNow(Duration.ofSeconds(5));
+        }
+    }
+
+    /**
+     * Collects one command: lines plus the literals they announce. A synchronizing literal {n} gets "+ Ready" first;
+     * {n+} (LITERAL+) is read at once. Marks whether the command was read behind TLS.
+     */
+    static final class CommandDecoder extends ByteToMessageDecoder {
+        private final int maxLiteral;
+        private final ByteArrayOutputStream command = new ByteArrayOutputStream();
+        private int literalLeft;
+        private int lineBytes;
+
+        CommandDecoder(int maxLiteral) {
+            this.maxLiteral = maxLiteral;
+        }
+
+        @Override
+        protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
+            while (in.isReadable()) {
+                if (literalLeft > 0) {
+                    int n = Math.min(literalLeft, in.readableBytes());
+                    byte[] chunk = new byte[n];
+                    in.readBytes(chunk);
+                    command.write(chunk, 0, n);
+                    literalLeft -= n;
+                    continue;
+                }
+                int newline = in.indexOf(in.readerIndex(), in.writerIndex(), (byte) '\n');
+                if (newline < 0) {
+                    if (lineBytes + in.readableBytes() > MAX_LINE) {
+                        throw new TooLongFrameException("Command line too long");
+                    }
+                    return;
+                }
+                int length = newline - in.readerIndex() + 1;
+                if (lineBytes + length > MAX_LINE) {
+                    throw new TooLongFrameException("Command line too long");
+                }
+                byte[] line = new byte[length];
+                in.readBytes(line);
+                command.write(line, 0, line.length);
+                lineBytes += length;
+                Matcher literal = LITERAL.matcher(new String(line, StandardCharsets.ISO_8859_1));
+                if (literal.find()) {
+                    long size = Long.parseLong(literal.group(1));
+                    if (size > maxLiteral) {
+                        ctx.writeAndFlush(Unpooled.copiedBuffer("* BYE Literal too large\r\n", StandardCharsets.US_ASCII));
+                        throw new TooLongFrameException("Literal too large: " + size);
+                    }
+                    literalLeft = (int) size;
+                    if (literal.group(2).isEmpty()) {
+                        ctx.writeAndFlush(Unpooled.copiedBuffer("+ Ready for literal data\r\n", StandardCharsets.US_ASCII));
+                    }
+                    continue;
+                }
+                out.add(new Command(command.toByteArray(), ctx.pipeline().get(SslHandler.class) != null));
+                command.reset();
+                lineBytes = 0;
+            }
+        }
+    }
+}

backend/src/main/java/com/mailserver/imap/ImapStore.java

@@ -0,0 +1,91 @@
+package com.mailserver.imap;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Locale;
+
+/**
+ * Mailboxes and messages as IMAP sees them. Blocking: the IMAP server calls it from a worker thread,
+ * never from the network event loop.
+ */
+public interface ImapStore {
+
+    /** A refusal the client sees as "NO reason". */
+    final class Refused extends RuntimeException {
+        public Refused(String reason) {
+            super(reason);
+        }
+    }
+
+    record Account(long userId, String email) {
+    }
+
+    record Mailbox(long id, String name, boolean system, long uidValidity, long uidNext) {
+
+        boolean isInbox() {
+            return system && "INBOX".equalsIgnoreCase(name);
+        }
+
+        boolean isDrafts() {
+            return system && "Drafts".equals(name);
+        }
+
+        /** RFC 6154 attribute, or null. */
+        String specialUse() {
+            if (!system) {
+                return null;
+            }
+            return switch (name) {
+                case "Drafts" -> "\\Drafts";
+                case "Sent" -> "\\Sent";
+                case "Spam" -> "\\Junk";
+                case "Trash" -> "\\Trash";
+                default -> null;
+            };
+        }
+
+        boolean named(String other) {
+            return isInbox() ? "INBOX".equalsIgnoreCase(other) : name.toLowerCase(Locale.ROOT).equals(other.toLowerCase(Locale.ROOT));
+        }
+    }
+
+    record Entry(long id, long uid, boolean seen, boolean flagged, boolean answered, boolean deleted, Instant internalDate) {
+
+        Entry withFlags(boolean seen, boolean flagged, boolean answered, boolean deleted) {
+            return new Entry(id, uid, seen, flagged, answered, deleted, internalDate);
+        }
+    }
+
+    /** null — wrong user or password. */
+    Account authenticate(String username, String password);
+
+    List<Mailbox> mailboxes(long userId);
+
+    Mailbox create(long userId, String name);
+
+    void rename(long userId, Mailbox mailbox, String newName);
+
+    /** An own folder: its messages go to the Trash (as in the web client), then the folder is removed. */
+    void delete(long userId, Mailbox mailbox);
+
+    /** Messages of the folder in UID order. */
+    List<Entry> entries(long folderId);
+
+    /** The full MIME text of the message (the original one, or built once and kept). */
+    byte[] source(long messageId);
+
+    void setFlags(long messageId, boolean seen, boolean flagged, boolean answered, boolean deleted);
+
+    /** Stores the message into the folder; returns its UID. */
+    long append(long userId, Mailbox target, byte[] raw, boolean seen, boolean flagged, boolean answered,
+                boolean deleted, Instant internalDate);
+
+    /** Copies; returns the new UIDs in the same order. */
+    List<Long> copy(long userId, List<Entry> messages, Mailbox target);
+
+    /** Moves; returns the new UIDs in the same order. */
+    List<Long> move(long userId, List<Entry> messages, Mailbox target);
+
+    /** Removes the messages for good (with attachment files). */
+    void expunge(List<Long> messageIds);
+}

backend/src/main/java/com/mailserver/imap/ImapWriter.java

@@ -0,0 +1,255 @@
+package com.mailserver.imap;
+
+import jakarta.mail.internet.AddressException;
+import jakarta.mail.internet.ContentDisposition;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeUtility;
+import jakarta.mail.internet.ParameterList;
+import jakarta.mail.internet.ParseException;
+
+import java.io.ByteArrayOutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
+import java.util.Enumeration;
+import java.util.Locale;
+
+/** Builds IMAP response bytes: strings, literals, ENVELOPE, BODYSTRUCTURE (RFC 3501 7.4.2). */
+final class ImapWriter {
+
+    private final ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+    ImapWriter text(String text) {
+        byte[] bytes = text.getBytes(StandardCharsets.UTF_8);
+        out.write(bytes, 0, bytes.length);
+        return this;
+    }
+
+    ImapWriter sp() {
+        out.write(' ');
+        return this;
+    }
+
+    ImapWriter crlf() {
+        return text("\r\n");
+    }
+
+    ImapWriter literal(byte[] bytes) {
+        text("{" + bytes.length + "}\r\n");
+        out.write(bytes, 0, bytes.length);
+        return this;
+    }
+
+    /** Quoted when it is plain ASCII without CR/LF, a literal otherwise; null → NIL. */
+    ImapWriter nstring(String value) {
+        if (value == null) {
+            return text("NIL");
+        }
+        return string(value);
+    }
+
+    ImapWriter string(String value) {
+        boolean quotable = value.length() < 1024;
+        for (int i = 0; i < value.length() && quotable; i++) {
+            char c = value.charAt(i);
+            if (c > 0x7e || c < 0x20) {
+                quotable = false;
+            }
+        }
+        if (!quotable) {
+            return literal(value.getBytes(StandardCharsets.UTF_8));
+        }
+        return text("\"" + value.replace("\\", "\\\\").replace("\"", "\\\"") + "\"");
+    }
+
+    byte[] bytes() {
+        return out.toByteArray();
+    }
+
+    // ---------- ENVELOPE ----------
+
+    ImapWriter envelope(MimeTree message) {
+        text("(");
+        nstring(message.header("Date")).sp();
+        nstring(message.header("Subject")).sp();
+        String from = message.header("From");
+        addresses(from).sp();
+        addresses(firstNonNull(message.header("Sender"), from)).sp();
+        addresses(firstNonNull(message.header("Reply-To"), from)).sp();
+        addresses(message.header("To")).sp();
+        addresses(message.header("Cc")).sp();
+        addresses(message.header("Bcc")).sp();
+        nstring(message.header("In-Reply-To")).sp();
+        nstring(message.header("Message-ID"));
+        return text(")");
+    }
+
+    private ImapWriter addresses(String header) {
+        if (header == null || header.isBlank()) {
+            return text("NIL");
+        }
+        InternetAddress[] list;
+        try {
+            list = InternetAddress.parseHeader(header, false);
+        } catch (AddressException e) {
+            return text("NIL");
+        }
+        if (list.length == 0) {
+            return text("NIL");
+        }
+        text("(");
+        for (InternetAddress address : list) {
+            String email = address.getAddress() == null ? "" : address.getAddress();
+            int at = email.lastIndexOf('@');
+            text("(");
+            nstring(encodedPersonal(address.getPersonal())).sp().text("NIL").sp();
+            nstring(at > 0 ? email.substring(0, at) : email).sp();
+            nstring(at > 0 ? email.substring(at + 1) : null);
+            text(")");
+        }
+        return text(")");
+    }
+
+    private static String encodedPersonal(String personal) {
+        if (personal == null) {
+            return null;
+        }
+        try {
+            return MimeUtility.encodeWord(personal, "UTF-8", "B");
+        } catch (UnsupportedEncodingException e) {
+            return personal;
+        }
+    }
+
+    // ---------- BODYSTRUCTURE / BODY ----------
+
+    ImapWriter bodyStructure(MimeTree part, boolean extensible) {
+        text("(");
+        if (part.isMultipart() && !part.children.isEmpty()) {
+            for (MimeTree child : part.children) {
+                bodyStructure(child, extensible);
+            }
+            sp().string(part.type.getSubType().toUpperCase(Locale.ROOT));
+            if (extensible) {
+                sp().params(part.type.getParameterList()).sp();
+                disposition(part).sp().text("NIL NIL");
+            }
+            return text(")");
+        }
+        String primary = part.isMultipart() ? "TEXT" : part.type.getPrimaryType().toUpperCase(Locale.ROOT);
+        String sub = part.isMultipart() ? "PLAIN" : part.type.getSubType().toUpperCase(Locale.ROOT);
+        string(primary).sp().string(sub).sp();
+        params(part.type.getParameterList()).sp();
+        nstring(part.header("Content-ID")).sp();
+        nstring(part.header("Content-Description")).sp();
+        String encoding = part.header("Content-Transfer-Encoding");
+        string(encoding == null ? "7BIT" : encoding.toUpperCase(Locale.ROOT)).sp();
+        text(String.valueOf(part.bodySize()));
+        if ("TEXT".equals(primary)) {
+            sp().text(String.valueOf(part.bodyLines()));
+        } else if (part.message != null) {
+            sp().envelope(part.message).sp().bodyStructure(part.message, extensible).sp().text(String.valueOf(part.bodyLines()));
+        }
+        if (extensible) {
+            sp().nstring(part.header("Content-MD5")).sp();
+            disposition(part).sp();
+            nstring(part.header("Content-Language")).sp();
+            nstring(part.header("Content-Location"));
+        }
+        return text(")");
+    }
+
+    private ImapWriter params(ParameterList params) {
+        if (params == null || params.size() == 0) {
+            return text("NIL");
+        }
+        text("(");
+        boolean first = true;
+        Enumeration<String> names = params.getNames();
+        while (names.hasMoreElements()) {
+            String name = names.nextElement();
+            if (!first) {
+                sp();
+            }
+            first = false;
+            string(name.toUpperCase(Locale.ROOT)).sp().string(String.valueOf(params.get(name)));
+        }
+        return text(")");
+    }
+
+    private ImapWriter disposition(MimeTree part) {
+        String header = part.header("Content-Disposition");
+        if (header == null) {
+            return text("NIL");
+        }
+        try {
+            ContentDisposition disposition = new ContentDisposition(header);
+            text("(").string(disposition.getDisposition().toUpperCase(Locale.ROOT)).sp();
+            params(disposition.getParameterList());
+            return text(")");
+        } catch (ParseException e) {
+            return text("NIL");
+        }
+    }
+
+    private static String firstNonNull(String a, String b) {
+        return a != null ? a : b;
+    }
+
+    // ---------- modified UTF-7 (RFC 3501 5.1.3) for mailbox names ----------
+
+    static String encodeMailbox(String name) {
+        StringBuilder out = new StringBuilder();
+        StringBuilder pending = new StringBuilder();
+        for (int i = 0; i < name.length(); i++) {
+            char c = name.charAt(i);
+            if (c >= 0x20 && c <= 0x7e) {
+                flushBase64(out, pending);
+                out.append(c == '&' ? "&-" : String.valueOf(c));
+            } else {
+                pending.append(c);
+            }
+        }
+        flushBase64(out, pending);
+        return out.toString();
+    }
+
+    private static void flushBase64(StringBuilder out, StringBuilder pending) {
+        if (pending.length() == 0) {
+            return;
+        }
+        byte[] utf16 = pending.toString().getBytes(StandardCharsets.UTF_16BE);
+        String base64 = java.util.Base64.getEncoder().withoutPadding().encodeToString(utf16).replace('/', ',');
+        out.append('&').append(base64).append('-');
+        pending.setLength(0);
+    }
+
+    static String decodeMailbox(String name) {
+        StringBuilder out = new StringBuilder();
+        int i = 0;
+        while (i < name.length()) {
+            char c = name.charAt(i);
+            if (c != '&') {
+                out.append(c);
+                i++;
+                continue;
+            }
+            int dash = name.indexOf('-', i);
+            if (dash < 0) {
+                out.append(name.substring(i));
+                break;
+            }
+            if (dash == i + 1) {
+                out.append('&');
+            } else {
+                try {
+                    byte[] utf16 = java.util.Base64.getDecoder().decode(name.substring(i + 1, dash).replace(',', '/'));
+                    out.append(new String(utf16, StandardCharsets.UTF_16BE));
+                } catch (IllegalArgumentException e) {
+                    out.append(name, i, dash + 1);
+                }
+            }
+            i = dash + 1;
+        }
+        return out.toString();
+    }
+}

backend/src/main/java/com/mailserver/imap/MimeSource.java

@@ -0,0 +1,129 @@
+package com.mailserver.imap;
+
+import com.mailserver.domain.Attachment;
+import com.mailserver.domain.Message;
+import jakarta.activation.DataHandler;
+import jakarta.activation.FileDataSource;
+import jakarta.mail.MessagingException;
+import jakarta.mail.Session;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeBodyPart;
+import jakarta.mail.internet.MimeMessage;
+import jakarta.mail.internet.MimeMultipart;
+import jakarta.mail.internet.MimeUtility;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.Properties;
+
+/**
+ * MIME text of a message that has no original (written in the web client): built from the stored fields and
+ * attachment files. The boundary and Message-ID come from the message id, so the result is the same every time.
+ */
+public final class MimeSource {
+
+    private MimeSource() {
+    }
+
+    public static byte[] build(Message message, List<Attachment> attachments, String hostname)
+            throws MessagingException, IOException {
+        Properties props = new Properties();
+        props.put("mail.mime.splitlongparameters", "true");
+        Session session = Session.getInstance(props);
+        String messageId = message.getMessageId() == null || message.getMessageId().isBlank()
+                ? message.getId() + "@" + hostname
+                : message.getMessageId().replaceAll("^<|>$", "");
+        if (!messageId.contains("@")) {
+            messageId = messageId + "@" + hostname;
+        }
+        String finalMessageId = "<" + messageId + ">";
+        MimeMessage mime = new MimeMessage(session) {
+            @Override
+            protected void updateMessageID() throws MessagingException {
+                setHeader("Message-ID", finalMessageId);
+            }
+        };
+
+        String from = message.getSenderEmail() == null ? "unknown@" + hostname : message.getSenderEmail();
+        mime.setFrom(new InternetAddress(from, message.getSenderName(), "UTF-8"));
+        List<InternetAddress> to = addresses(message.getRecipientEmail());
+        if (!to.isEmpty()) {
+            mime.setRecipients(jakarta.mail.Message.RecipientType.TO, to.toArray(new InternetAddress[0]));
+        }
+        List<InternetAddress> cc = addresses(message.getCcEmail());
+        if (!cc.isEmpty()) {
+            mime.setRecipients(jakarta.mail.Message.RecipientType.CC, cc.toArray(new InternetAddress[0]));
+        }
+        mime.setSubject(message.getSubject() == null ? "" : message.getSubject(), "UTF-8");
+        if (message.getReceivedAt() != null) {
+            mime.setSentDate(Date.from(message.getReceivedAt()));
+        }
+
+        String body = message.getBody() == null ? "" : message.getBody();
+        String subtype = message.isHtml() ? "html" : "plain";
+        if (attachments.isEmpty()) {
+            mime.setText(body, "UTF-8", subtype);
+        } else {
+            MimeMultipart mixed = new FixedBoundaryMultipart("mixed", "=_rms_" + message.getId());
+            MimeBodyPart text = new MimeBodyPart();
+            text.setText(body, "UTF-8", subtype);
+            mixed.addBodyPart(text);
+            for (Attachment attachment : attachments) {
+                Path file = Path.of(attachment.getFilePath());
+                if (!Files.isRegularFile(file)) {
+                    continue;
+                }
+                MimeBodyPart part = new MimeBodyPart();
+                FileDataSource source = new FileDataSource(file.toFile()) {
+                    @Override
+                    public String getContentType() {
+                        return attachment.getContentType() == null ? "application/octet-stream" : attachment.getContentType();
+                    }
+                };
+                part.setDataHandler(new DataHandler(source));
+                part.setFileName(MimeUtility.encodeText(attachment.getFilename(), "UTF-8", null));
+                part.setDisposition(attachment.getContentId() != null ? MimeBodyPart.INLINE : MimeBodyPart.ATTACHMENT);
+                if (attachment.getContentId() != null) {
+                    part.setContentID("<" + attachment.getContentId().replaceAll("^<|>$", "") + ">");
+                }
+                mixed.addBodyPart(part);
+            }
+            mime.setContent(mixed);
+        }
+        mime.saveChanges();
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        mime.writeTo(out);
+        return out.toByteArray();
+    }
+
+    private static List<InternetAddress> addresses(String list) {
+        List<InternetAddress> result = new ArrayList<>();
+        if (list == null || list.isBlank()) {
+            return result;
+        }
+        for (String one : list.split("[,;]")) {
+            String address = one.trim();
+            if (!address.isEmpty()) {
+                try {
+                    result.add(new InternetAddress(address));
+                } catch (MessagingException ignored) {
+                    // a broken address is left out, the message is still served
+                }
+            }
+        }
+        return result;
+    }
+
+    /** MimeMultipart with a given boundary instead of a random one. */
+    private static final class FixedBoundaryMultipart extends MimeMultipart {
+        FixedBoundaryMultipart(String subtype, String boundary) {
+            super(subtype);
+            this.contentType = "multipart/" + subtype + "; boundary=\"" + boundary + "\"";
+        }
+    }
+}

backend/src/main/java/com/mailserver/imap/MimeTree.java

@@ -0,0 +1,250 @@
+package com.mailserver.imap;
+
+import jakarta.mail.MessagingException;
+import jakarta.mail.internet.ContentType;
+import jakarta.mail.internet.InternetHeaders;
+import jakarta.mail.internet.ParseException;
+
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.Locale;
+import java.util.Set;
+
+/**
+ * A message split into MIME parts by byte offsets — what IMAP needs for BODYSTRUCTURE and BODY[section]:
+ * every part is a range of the original bytes, so sizes and contents match BODY[] exactly.
+ */
+final class MimeTree {
+
+    private static final int MAX_DEPTH = 20;
+
+    final byte[] raw;
+    /** Part = [start, end); headers = [start, bodyStart), the blank line included. */
+    final int start;
+    final int bodyStart;
+    final int end;
+    final InternetHeaders headers;
+    final ContentType type;
+    final List<MimeTree> children;
+    /** The encapsulated message of a message/rfc822 part. */
+    final MimeTree message;
+
+    private MimeTree(byte[] raw, int start, int end, int depth) {
+        this.raw = raw;
+        this.start = start;
+        this.end = end;
+        this.bodyStart = headerEnd(raw, start, end);
+        this.headers = parseHeaders(raw, start, bodyStart);
+        this.type = contentType(headers);
+        List<MimeTree> parts = new ArrayList<>();
+        MimeTree nested = null;
+        if (depth < MAX_DEPTH) {
+            if (isMultipart()) {
+                String boundary = type.getParameter("boundary");
+                if (boundary != null && !boundary.isEmpty()) {
+                    split(boundary, depth, parts);
+                }
+            } else if (is("message", "rfc822") || is("message", "global")) {
+                nested = new MimeTree(raw, bodyStart, end, depth + 1);
+            }
+        }
+        this.children = Collections.unmodifiableList(parts);
+        this.message = nested;
+    }
+
+    static MimeTree parse(byte[] raw) {
+        return new MimeTree(raw, 0, raw.length, 0);
+    }
+
+    boolean isMultipart() {
+        return "multipart".equalsIgnoreCase(type.getPrimaryType());
+    }
+
+    boolean is(String primary, String sub) {
+        return primary.equalsIgnoreCase(type.getPrimaryType()) && sub.equalsIgnoreCase(type.getSubType());
+    }
+
+    byte[] all() {
+        return slice(start, end);
+    }
+
+    byte[] header() {
+        return slice(start, bodyStart);
+    }
+
+    byte[] body() {
+        return slice(bodyStart, end);
+    }
+
+    int bodySize() {
+        return end - bodyStart;
+    }
+
+    /** Lines of the body (for text parts in BODYSTRUCTURE). */
+    int bodyLines() {
+        int lines = 0;
+        for (int i = bodyStart; i < end; i++) {
+            if (raw[i] == '\n') {
+                lines++;
+            }
+        }
+        if (end > bodyStart && raw[end - 1] != '\n') {
+            lines++;
+        }
+        return lines;
+    }
+
+    /** Header value unfolded, or null. */
+    String header(String name) {
+        String[] values = headers.getHeader(name);
+        if (values == null || values.length == 0 || values[0] == null) {
+            return null;
+        }
+        return values[0].replaceAll("\r?\n(?=[ \t])", "").trim();
+    }
+
+    /** Only these header fields (or all but these), each with its folded lines, plus the blank line. */
+    byte[] headerFields(Set<String> names, boolean not) {
+        StringBuilder out = new StringBuilder();
+        String text = new String(raw, start, bodyStart - start, StandardCharsets.ISO_8859_1);
+        String[] lines = text.split("\r?\n", -1);
+        boolean keep = false;
+        for (String line : lines) {
+            if (line.isEmpty()) {
+                continue;
+            }
+            if (line.charAt(0) == ' ' || line.charAt(0) == '\t') {
+                if (keep) {
+                    out.append(line).append("\r\n");
+                }
+                continue;
+            }
+            int colon = line.indexOf(':');
+            String name = colon > 0 ? line.substring(0, colon).trim().toUpperCase(Locale.ROOT) : "";
+            keep = names.contains(name) != not;
+            if (keep) {
+                out.append(line).append("\r\n");
+            }
+        }
+        out.append("\r\n");
+        return out.toString().getBytes(StandardCharsets.ISO_8859_1);
+    }
+
+    private byte[] slice(int from, int to) {
+        byte[] copy = new byte[Math.max(0, to - from)];
+        System.arraycopy(raw, from, copy, 0, copy.length);
+        return copy;
+    }
+
+    /** Body parts between "--boundary" lines; the CRLF before a delimiter belongs to the delimiter. */
+    private void split(String boundary, int depth, List<MimeTree> parts) {
+        byte[] delimiter = ("--" + boundary).getBytes(StandardCharsets.ISO_8859_1);
+        int partStart = -1;
+        int i = bodyStart;
+        while (i < end) {
+            int lineEnd = indexOf(raw, (byte) '\n', i, end);
+            int next = lineEnd < 0 ? end : lineEnd + 1;
+            if (startsWith(raw, i, end, delimiter)) {
+                int after = i + delimiter.length;
+                boolean close = after + 1 < end && raw[after] == '-' && raw[after + 1] == '-';
+                if (partStart >= 0) {
+                    int partEnd = i;
+                    if (partEnd > partStart && raw[partEnd - 1] == '\n') {
+                        partEnd--;
+                        if (partEnd > partStart && raw[partEnd - 1] == '\r') {
+                            partEnd--;
+                        }
+                    }
+                    parts.add(new MimeTree(raw, partStart, Math.max(partStart, partEnd), depth + 1));
+                }
+                if (close) {
+                    return;
+                }
+                partStart = next;
+            }
+            i = next;
+        }
+        if (partStart >= 0 && partStart < end) { // no closing delimiter — take the rest
+            parts.add(new MimeTree(raw, partStart, end, depth + 1));
+        }
+    }
+
+    private static int headerEnd(byte[] raw, int start, int end) {
+        if (start < end && raw[start] == '\n') {
+            return start + 1;
+        }
+        if (start + 1 < end && raw[start] == '\r' && raw[start + 1] == '\n') {
+            return start + 2;
+        }
+        for (int i = start; i < end; i++) {
+            if (raw[i] == '\n') {
+                if (i + 1 < end && raw[i + 1] == '\n') {
+                    return i + 2;
+                }
+                if (i + 2 < end && raw[i + 1] == '\r' && raw[i + 2] == '\n') {
+                    return i + 3;
+                }
+            }
+        }
+        return end; // headers only
+    }
+
+    private static InternetHeaders parseHeaders(byte[] raw, int start, int end) {
+        try {
+            return new InternetHeaders(new ByteArrayInputStream(raw, start, end - start));
+        } catch (MessagingException e) {
+            return new InternetHeaders();
+        }
+    }
+
+    private static ContentType contentType(InternetHeaders headers) {
+        String[] values = headers.getHeader("Content-Type");
+        if (values != null && values.length > 0 && values[0] != null) {
+            try {
+                return new ContentType(values[0].replaceAll("\r?\n(?=[ \t])", "").trim());
+            } catch (ParseException ignored) {
+                // broken header — the RFC 2045 default
+            }
+        }
+        try {
+            return new ContentType("text/plain; charset=us-ascii");
+        } catch (ParseException e) {
+            throw new IllegalStateException(e);
+        }
+    }
+
+    private static boolean startsWith(byte[] raw, int at, int end, byte[] prefix) {
+        if (at + prefix.length > end) {
+            return false;
+        }
+        for (int i = 0; i < prefix.length; i++) {
+            if (raw[at + i] != prefix[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static int indexOf(byte[] raw, byte value, int from, int end) {
+        for (int i = from; i < end; i++) {
+            if (raw[i] == value) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /** Header names of the part, for tests and debugging. */
+    List<String> headerNames() {
+        List<String> names = new ArrayList<>();
+        Enumeration<jakarta.mail.Header> all = headers.getAllHeaders();
+        while (all.hasMoreElements()) {
+            names.add(all.nextElement().getName());
+        }
+        return names;
+    }
+}

backend/src/main/java/com/mailserver/repository/AttachmentRepository.java

@@ -1,9 +1,22 @@
 package com.mailserver.repository;
 
 import com.mailserver.domain.Attachment;
+import org.springframework.data.r2dbc.repository.Modifying;
+import org.springframework.data.r2dbc.repository.Query;
 import org.springframework.data.r2dbc.repository.R2dbcRepository;
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 public interface AttachmentRepository extends R2dbcRepository<Attachment, Long> {
     Flux<Attachment> findByMessageId(Long messageId);
+
+    Mono<Long> countByMessageId(Long messageId);
+
+    @Modifying
+    @Query("UPDATE attachments SET message_id = :#{#to} WHERE message_id = :#{#from}")
+    Mono<Integer> moveAll(Long from, Long to);
+
+    @Query("SELECT COALESCE(SUM(a.size_bytes), 0) FROM attachments a JOIN messages m ON m.id = a.message_id " +
+           "JOIN folders f ON f.id = m.folder_id WHERE f.user_id = :#{#userId}")
+    Mono<Long> sumSizeByUserId(Long userId);
 }

backend/src/main/java/com/mailserver/repository/MessageRepository.java

@@ -2,6 +2,7 @@ package com.mailserver.repository;
 
 import com.mailserver.domain.Message;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.r2dbc.repository.Modifying;
 import org.springframework.data.r2dbc.repository.Query;
 import org.springframework.data.r2dbc.repository.R2dbcRepository;
 import reactor.core.publisher.Flux;
@@ -9,19 +10,29 @@ import reactor.core.publisher.Mono;
 
 public interface MessageRepository extends R2dbcRepository<Message, Long> {
 
-    @Query("SELECT * FROM messages WHERE folder_id = :#{#folderId} ORDER BY received_at DESC")
+    @Query("SELECT * FROM messages WHERE folder_id = :#{#folderId} ORDER BY received_at DESC LIMIT :#{#limit}")
-    Flux<Message> findByFolderId(Long folderId, Pageable pageable);
+    Flux<Message> findLatest(Long folderId, int limit);
+
+    Flux<Message> findByFolderId(Long folderId);
+
+    @Query("SELECT COUNT(*) FROM messages WHERE folder_id = :#{#folderId}")
+    Mono<Long> countByFolderId(Long folderId);
 
     @Query("SELECT COUNT(*) FROM messages WHERE folder_id = :#{#folderId} AND is_read = false")
     Mono<Long> countUnreadByFolderId(Long folderId);
 
-    @Query("SELECT * FROM messages WHERE folder_id = :#{#folderId} AND is_read = false ORDER BY received_at DESC")
+    @Modifying
-    Flux<Message> findUnreadByFolderId(Long folderId, Pageable pageable);
+    @Query("UPDATE messages SET folder_id = :#{#to} WHERE folder_id = :#{#from}")
+    Mono<Integer> moveAll(Long from, Long to);
+
+    @Query("SELECT COALESCE(SUM(m.message_size), 0) FROM messages m JOIN folders f ON f.id = m.folder_id WHERE f.user_id = :#{#userId}")
+    Mono<Long> sumSizeByUserId(Long userId);
 
     @Query("SELECT * FROM messages WHERE folder_id = :#{#folderId} AND " +
            "(LOWER(subject) LIKE '%' || LOWER(:#{#keyword}) || '%' OR " +
            "LOWER(sender_email) LIKE '%' || LOWER(:#{#keyword}) || '%' OR " +
            "LOWER(sender_name) LIKE '%' || LOWER(:#{#keyword}) || '%' OR " +
+           "LOWER(recipient_email) LIKE '%' || LOWER(:#{#keyword}) || '%' OR " +
            "LOWER(body) LIKE '%' || LOWER(:#{#keyword}) || '%') " +
            "ORDER BY received_at DESC")
     Flux<Message> searchInFolder(Long folderId, String keyword, Pageable pageable);

backend/src/main/java/com/mailserver/security/LoginGuard.java

@@ -0,0 +1,257 @@
+package com.mailserver.security;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.scheduling.annotation.Scheduled;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.LinkedHashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Brute-force protection for every place that checks a password: SMTP AUTH, IMAP LOGIN/AUTHENTICATE, web login,
+ * password change. One instance is shared by all of them, so failures on SMTP and IMAP add up.
+ * <ul>
+ *   <li><b>By IP:</b> {@code maxPerIp} failures within {@code window} → the IP is blocked for {@code block};
+ *       each next block of the same IP is twice as long, up to {@code maxBlock}.</li>
+ *   <li><b>By mailbox:</b> {@code maxPerAccount} failures within {@code window} from any IPs (a distributed attack on
+ *       one mailbox) → the mailbox is blocked for {@code block} — but not for IPs that logged in to it successfully
+ *       before ({@code knownIpTtl}), so an attacker cannot lock the owner's own mail program out.</li>
+ * </ul>
+ * While blocked the password is not checked at all (no answer to a guess) and the caller gets {@link #retryAfter}.
+ * State is in memory: a restart forgets it, which is fine for minutes-long blocks.
+ */
+public class LoginGuard {
+
+    private static final Logger log = LoggerFactory.getLogger(LoginGuard.class);
+
+    /** Upper bound of tracked keys of each kind, so a flood of random usernames/IPs cannot eat the memory. */
+    static final int MAX_KEYS = 100_000;
+    private static final int MAX_KNOWN_IPS_PER_ACCOUNT = 20;
+
+    public record Settings(boolean enabled, int maxPerIp, int maxPerAccount, Duration window, Duration block,
+                           Duration maxBlock, Duration knownIpTtl, Set<String> trustedIps, Duration failureDelay) {
+
+        public static Settings defaults() {
+            return new Settings(true, 10, 20, Duration.ofMinutes(15), Duration.ofMinutes(15), Duration.ofHours(24),
+                    Duration.ofDays(30), Set.of(), Duration.ofSeconds(1));
+        }
+    }
+
+    /** Failures in the window, current block and how many times the key was blocked in a row. */
+    private static final class Counter {
+        final Deque<Instant> failures = new ArrayDeque<>();
+        volatile Instant blockedUntil = Instant.EPOCH;
+        int strikes;
+        Instant lastSeen = Instant.EPOCH;
+    }
+
+    private final Settings settings;
+    private final Clock clock;
+    private final Map<String, Counter> byIp = new ConcurrentHashMap<>();
+    private final Map<String, Counter> byAccount = new ConcurrentHashMap<>();
+    /** account → IPs that logged in to it successfully, with the time of the last success. */
+    private final Map<String, Map<String, Instant>> knownIps = new ConcurrentHashMap<>();
+
+    public LoginGuard(Settings settings) {
+        this(settings, Clock.systemUTC());
+    }
+
+    LoginGuard(Settings settings, Clock clock) {
+        this.settings = settings;
+        this.clock = clock;
+    }
+
+    /** Guard that never blocks (tests, closed networks). */
+    public static LoginGuard disabled() {
+        Settings d = Settings.defaults();
+        return new LoginGuard(new Settings(false, d.maxPerIp(), d.maxPerAccount(), d.window(), d.block(), d.maxBlock(),
+                d.knownIpTtl(), Set.of(), Duration.ZERO));
+    }
+
+    /** Pause before answering "wrong password": slows down guessing inside one connection. */
+    public Duration failureDelay() {
+        return settings.enabled() ? settings.failureDelay() : Duration.ZERO;
+    }
+
+    /**
+     * Zero when the attempt may go on and the password may be checked; otherwise how long the caller has to wait.
+     */
+    public Duration retryAfter(String ip, String account) {
+        if (!settings.enabled()) {
+            return Duration.ZERO;
+        }
+        Instant now = clock.instant();
+        Duration wait = Duration.ZERO;
+        if (!trusted(ip)) {
+            wait = remaining(byIp.get(ip), now);
+        }
+        String acc = normalize(account);
+        if (acc != null && !known(acc, ip, now)) {
+            Duration accountWait = remaining(byAccount.get(acc), now);
+            if (accountWait.compareTo(wait) > 0) {
+                wait = accountWait;
+            }
+        }
+        return wait;
+    }
+
+    public boolean blocked(String ip, String account) {
+        return !retryAfter(ip, account).isZero();
+    }
+
+    /** A wrong password (or an unknown mailbox). */
+    public void failure(String ip, String account) {
+        if (!settings.enabled()) {
+            return;
+        }
+        Instant now = clock.instant();
+        if (!trusted(ip)) {
+            count(byIp, ip, settings.maxPerIp(), now, "IP " + ip);
+        }
+        String acc = normalize(account);
+        if (acc != null) {
+            count(byAccount, acc, settings.maxPerAccount(), now, "mailbox " + acc);
+        }
+    }
+
+    /** A right password: the IP becomes known for the mailbox, failures of this IP are forgiven. */
+    public void success(String ip, String account) {
+        if (!settings.enabled()) {
+            return;
+        }
+        Instant now = clock.instant();
+        String acc = normalize(account);
+        if (acc != null) {
+            if (knownIps.size() < MAX_KEYS || knownIps.containsKey(acc)) {
+                knownIps.compute(acc, (k, ips) -> {
+                    Map<String, Instant> map = ips != null ? ips : new LinkedHashMap<>();
+                    synchronized (map) {
+                        map.remove(ip);
+                        map.put(ip, now);
+                        while (map.size() > MAX_KNOWN_IPS_PER_ACCOUNT) {
+                            map.remove(map.keySet().iterator().next());
+                        }
+                    }
+                    return map;
+                });
+            }
+        }
+        byIp.computeIfPresent(ip, (k, c) -> {
+            c.failures.clear();
+            return c.blockedUntil.isAfter(now) ? c : null;
+        });
+    }
+
+    /** Drops what expired; runs every minute. */
+    @Scheduled(fixedDelay = 60_000)
+    public void sweep() {
+        Instant now = clock.instant();
+        Instant idle = now.minus(settings.maxBlock()).minus(settings.window());
+        byIp.entrySet().removeIf(e -> stale(e.getValue(), now, idle));
+        byAccount.entrySet().removeIf(e -> stale(e.getValue(), now, idle));
+        Instant knownSince = now.minus(settings.knownIpTtl());
+        knownIps.entrySet().removeIf(e -> {
+            synchronized (e.getValue()) {
+                e.getValue().values().removeIf(t -> t.isBefore(knownSince));
+                return e.getValue().isEmpty();
+            }
+        });
+    }
+
+    int trackedIps() {
+        return byIp.size();
+    }
+
+    int trackedAccounts() {
+        return byAccount.size();
+    }
+
+    // ---------------------------------------------------------------------------------------------
+
+    private void count(Map<String, Counter> map, String key, int max, Instant now, String what) {
+        if (map.size() >= MAX_KEYS && !map.containsKey(key)) {
+            sweep();
+            if (map.size() >= MAX_KEYS) {
+                log.warn("login guard: {} keys tracked, {} not counted", map.size(), what);
+                return;
+            }
+        }
+        map.compute(key, (k, existing) -> {
+            Counter c = existing != null ? existing : new Counter();
+            c.lastSeen = now;
+            Instant from = now.minus(settings.window());
+            while (!c.failures.isEmpty() && c.failures.peekFirst().isBefore(from)) {
+                c.failures.pollFirst();
+            }
+            if (c.blockedUntil.isAfter(now)) {
+                return c; // already blocked: attempts are refused before the password check anyway
+            }
+            // A long quiet time after the last block forgives the strikes
+            if (c.strikes > 0 && c.blockedUntil.plus(settings.maxBlock()).isBefore(now)) {
+                c.strikes = 0;
+            }
+            c.failures.addLast(now);
+            if (c.failures.size() >= max) {
+                Duration block = settings.block().multipliedBy(1L << Math.min(c.strikes, 20));
+                if (block.compareTo(settings.maxBlock()) > 0) {
+                    block = settings.maxBlock();
+                }
+                c.strikes++;
+                c.blockedUntil = now.plus(block);
+                c.failures.clear();
+                log.warn("login guard: {} blocked for {} after {} failed logins (block #{})",
+                        what, human(block), max, c.strikes);
+            }
+            return c;
+        });
+    }
+
+    private static Duration remaining(Counter c, Instant now) {
+        if (c == null) {
+            return Duration.ZERO;
+        }
+        Instant until = c.blockedUntil;
+        return until.isAfter(now) ? Duration.between(now, until) : Duration.ZERO;
+    }
+
+    private boolean known(String account, String ip, Instant now) {
+        Map<String, Instant> ips = knownIps.get(account);
+        if (ips == null) {
+            return false;
+        }
+        synchronized (ips) {
+            Instant at = ips.get(ip);
+            return at != null && at.plus(settings.knownIpTtl()).isAfter(now);
+        }
+    }
+
+    private boolean trusted(String ip) {
+        return settings.trustedIps().contains(ip);
+    }
+
+    private static boolean stale(Counter c, Instant now, Instant idle) {
+        return !c.blockedUntil.isAfter(now) && c.lastSeen.isBefore(idle);
+    }
+
+    private static String normalize(String account) {
+        if (account == null) {
+            return null;
+        }
+        String acc = account.trim().toLowerCase(Locale.ROOT);
+        return acc.isEmpty() ? null : acc;
+    }
+
+    /** "15 min" / "2 h" for messages to the user. */
+    public static String human(Duration d) {
+        long minutes = Math.max(1, (d.toSeconds() + 59) / 60);
+        return minutes < 120 ? minutes + " min" : (minutes + 59) / 60 + " h";
+    }
+}

backend/src/main/java/com/mailserver/service/DkimService.java

@@ -1,458 +1,209 @@
 package com.mailserver.service;
 
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.stereotype.Service;
-
 import jakarta.annotation.PostConstruct;
 import jakarta.mail.MessagingException;
+import jakarta.mail.Session;
+import jakarta.mail.internet.InternetAddress;
 import jakarta.mail.internet.MimeMessage;
-import org.springframework.core.io.ClassPathResource;
+import org.apache.james.jdkim.DKIMVerifier;
+import org.apache.james.jdkim.api.PublicKeyRecordRetriever;
+import org.apache.james.jdkim.api.SignatureRecord;
+import org.apache.james.jdkim.exceptions.FailException;
+import org.apache.james.jdkim.impl.DNSPublicKeyRecordRetriever;
+import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
+import org.bouncycastle.openssl.PEMKeyPair;
+import org.bouncycastle.openssl.PEMParser;
+import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
+import org.simplejavamail.utils.mail.dkim.Canonicalization;
+import org.simplejavamail.utils.mail.dkim.DkimMessage;
+import org.simplejavamail.utils.mail.dkim.DkimSigner;
+import org.simplejavamail.utils.mail.dkim.SigningAlgorithm;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
 
-import java.io.*;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.security.*;
+import java.nio.file.attribute.PosixFilePermissions;
-import java.security.spec.InvalidKeySpecException;
+import java.security.KeyFactory;
-import java.security.cert.CertificateException;
+import java.security.KeyPairGenerator;
-import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.interfaces.RSAPrivateCrtKey;
-import java.security.spec.X509EncodedKeySpec;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.spec.RSAPublicKeySpec;
 import java.util.Base64;
+import java.util.List;
+import java.util.Locale;
+import java.util.Properties;
 
 /**
- * Сервис для DKIM (DomainKeys Identified Mail) подписи и верификации писем.
+ * DKIM (RFC 6376): signs our outgoing mail and verifies incoming mail.
- *
+ * Signing — simple-java-mail utils-mail-dkim (rsa-sha256, relaxed/relaxed); verification — Apache James jDKIM
- * DKIM добавляет криптографическую подпись к каждому исходящему письму,
+ * with the sender's public key from DNS. The key is generated once and kept in {@code keys-dir/dkim-private.pem};
- * чтобы получатель мог проверить, что письмо действительно отправлено
+ * the DNS record to publish is printed to the log at start and available from {@link #dnsRecord()}.
- * владельцем домена и не было изменено в пути.
- *
- * При старте генерирует RSA-ключ (2048 бит) и сохраняет его в файл.
- * Подписывает заголовки From, Subject, Date, To и тело сообщения.
  */
 @Service
 public class DkimService {
 
     private static final Logger log = LoggerFactory.getLogger(DkimService.class);
 
-    private static final String DKIM_SELECTOR = "default";
+    /** Result of checking an incoming message. */
+    public record Verification(boolean signed, boolean passed, String domain) {
+        static final Verification NONE = new Verification(false, false, null);
+    }
 
-    @Value("${mailserver.dkim.domain:localhost}")
+    private final String domain;
-    private String domain;
+    private final String selector;
+    private final Path keysDir;
+    private final boolean enabled;
+    private final DKIMVerifier verifier;
 
-    @Value("${mailserver.dkim.keys-dir:./dkim-keys}")
+    private RSAPrivateKey privateKey;
-    private String keysDir;
-
-    @Value("${mailserver.dkim.enabled:true}")
-    private boolean enabled;
-
-    private PrivateKey privateKey;
-    private PublicKey publicKey;
     private String publicKeyBase64;
 
+    @Autowired
+    public DkimService(@Value("${mailserver.dkim.domain:localhost}") String domain,
+                       @Value("${mailserver.dkim.selector:mail}") String selector,
+                       @Value("${mailserver.dkim.keys-dir:./dkim-keys}") String keysDir,
+                       @Value("${mailserver.dkim.enabled:true}") boolean enabled) {
+        this(domain, selector, Paths.get(keysDir), enabled, new DNSPublicKeyRecordRetriever());
+    }
+
+    // Tests pass their own public key lookup instead of DNS
+    DkimService(String domain, String selector, Path keysDir, boolean enabled, PublicKeyRecordRetriever keys) {
+        this.domain = domain.toLowerCase(Locale.ROOT);
+        this.selector = selector;
+        this.keysDir = keysDir;
+        this.enabled = enabled;
+        this.verifier = new DKIMVerifier(keys);
+    }
+
     @PostConstruct
     public void init() {
-        Security.addProvider(new BouncyCastleProvider());
-
         if (!enabled) {
-            log.info("DKIM подписи отключены");
+            log.info("DKIM signing disabled");
             return;
         }
-
         try {
-            Path keyDir = Paths.get(keysDir);
+            Files.createDirectories(keysDir);
-            Files.createDirectories(keyDir);
+            Path keyFile = keysDir.resolve("dkim-private.pem");
-
+            if (Files.exists(keyFile)) {
-            Path privateKeyFile = keyDir.resolve("dkim-private.pem");
+                privateKey = readPrivateKey(Files.readString(keyFile));
-            Path publicKeyFile = keyDir.resolve("dkim-public.pem");
+                log.info("DKIM: key loaded for {}", domain);
-
-            if (Files.exists(privateKeyFile) && Files.exists(publicKeyFile)) {
-                // Загружаем существующие ключи
-                loadKeys(privateKeyFile, publicKeyFile);
-                log.info("DKIM: загружены существующие ключи для домена {}", domain);
             } else {
-                // Генерируем новые ключи
+                KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
-                KeyPair keyPair = generateKeyPair();
+                generator.initialize(2048);
-                privateKey = keyPair.getPrivate();
+                privateKey = (RSAPrivateKey) generator.generateKeyPair().getPrivate();
-                publicKey = keyPair.getPublic();
+                String pem = "-----BEGIN PRIVATE KEY-----\n"
-                saveKeys(privateKeyFile, publicKeyFile, keyPair);
+                        + Base64.getMimeEncoder(64, "\n".getBytes()).encodeToString(privateKey.getEncoded())
-                log.info("DKIM: сгенерированы новые ключи для домена {}", domain);
+                        + "\n-----END PRIVATE KEY-----\n";
+                Files.writeString(keyFile, pem);
+                restrict(keyFile);
+                log.info("DKIM: new key generated for {}", domain);
             }
-
+            publicKeyBase64 = Base64.getEncoder().encodeToString(publicKeyOf(privateKey));
-            // Формируем публичный ключ в формате DNS TXT-записи
+            log.info("DKIM DNS record — TXT {}._domainkey.{}: {}", selector, domain, dnsRecord());
-            publicKeyBase64 = encodePublicKeyForDns(publicKey);
-            log.info("DKIM публичный ключ для DNS TXT-записи (_{}._domainkey.{}):", DKIM_SELECTOR, domain);
-            log.info("v=DKIM1; k=rsa; p={}", publicKeyBase64);
-
         } catch (Exception e) {
-            log.error("Ошибка инициализации DKIM", e);
+            throw new IllegalStateException("DKIM key cannot be loaded from " + keysDir, e);
         }
     }
 
-    /**
+    /** TXT value to publish at {@code <selector>._domainkey.<domain>}. */
-     * Генерирует RSA-ключ 2048 бит для DKIM.
+    public String dnsRecord() {
-     */
+        return publicKeyBase64 == null ? null : "v=DKIM1; k=rsa; p=" + publicKeyBase64;
-    private KeyPair generateKeyPair() throws NoSuchAlgorithmException {
-        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
-        keyPairGenerator.initialize(2048);
-        return keyPairGenerator.generateKeyPair();
     }
 
     /**
-     * Сохраняет ключи в PEM-формат.
+     * Signs the message when it is from our domain; otherwise returns it unchanged.
+     * The result is the exact byte sequence to send — do not re-serialize it.
      */
-    private void saveKeys(Path privateKeyFile, Path publicKeyFile, KeyPair keyPair)
+    public byte[] sign(byte[] message) throws MessagingException, IOException {
-            throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
-        try (FileWriter fw = new FileWriter(privateKeyFile.toFile());
-             JcaPEMWriter pemWriter = new JcaPEMWriter(fw)) {
-            pemWriter.writeObject(keyPair.getPrivate());
-            pemWriter.flush();
-        }
-
-        try (FileWriter fw = new FileWriter(publicKeyFile.toFile());
-             JcaPEMWriter pemWriter = new JcaPEMWriter(fw)) {
-            pemWriter.writeObject(keyPair.getPublic());
-            pemWriter.flush();
-        }
-    }
-
-    /**
-     * Загружает ключи из PEM-файлов.
-     */
-    private void loadKeys(Path privateKeyFile, Path publicKeyFile)
-            throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
-        String pkcs8Private = Files.readString(privateKeyFile);
-        String derEncoded = pkcs8Private
-                .replace("-----BEGIN PRIVATE KEY-----", "")
-                .replace("-----END PRIVATE KEY-----", "")
-                .replaceAll("\\s", "");
-        byte[] decoded = Base64.getDecoder().decode(derEncoded);
-        PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(decoded);
-        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
-        privateKey = keyFactory.generatePrivate(spec);
-
-        String pkcs8Public = Files.readString(publicKeyFile);
-        String derEncodedPublic = pkcs8Public
-                .replace("-----BEGIN PUBLIC KEY-----", "")
-                .replace("-----END PUBLIC KEY-----", "")
-                .replaceAll("\\s", "");
-        byte[] decodedPublic = Base64.getDecoder().decode(derEncodedPublic);
-        X509EncodedKeySpec pubSpec = new X509EncodedKeySpec(decodedPublic);
-        publicKey = keyFactory.generatePublic(pubSpec);
-    }
-
-    /**
-     * Кодирует публичный ключ для DNS TXT-записи.
-     */
-    private String encodePublicKeyForDns(PublicKey key) {
-        byte[] encoded = key.getEncoded();
-        return Base64.getEncoder().withoutPadding().encodeToString(encoded);
-    }
-
-    /**
-     * Подписывает MIME-сообщение DKIM-подписью.
-     * Добавляет заголовок DKIM-Signature в письмо.
-     *
-     * @param mimeMessage MIME-сообщение для подписи
-     * @throws MessagingException если не удалось добавить заголовок
-     */
-    public void signMessage(MimeMessage mimeMessage) throws MessagingException {
         if (!enabled || privateKey == null) {
-            return;
+            return message;
         }
+        MimeMessage mime = new MimeMessage(Session.getInstance(new Properties()), new ByteArrayInputStream(message));
+        if (mime.getFrom() == null || mime.getFrom().length == 0
+                || !(mime.getFrom()[0] instanceof InternetAddress from)
+                || !domain.equals(domainOf(from.getAddress()))) {
+            return message;
+        }
+        DkimSigner signer = new DkimSigner(domain, selector, privateKey);
+        signer.setCheckDomainKey(false); // the DNS record may not be published yet (tests, new server)
+        signer.setSigningAlgorithm(SigningAlgorithm.SHA256_WITH_RSA);
+        signer.setHeaderCanonicalization(Canonicalization.RELAXED);
+        signer.setBodyCanonicalization(Canonicalization.RELAXED);
+        signer.setLengthParam(false);
+        signer.setCopyHeaderFields(false);
+        ByteArrayOutputStream out = new ByteArrayOutputStream(message.length + 1024);
+        DkimMessage signed = new DkimMessage(mime, signer);
+        signed.setAllow8bitMIME(true);
+        signed.writeTo(out);
+        return out.toByteArray();
+    }
 
+    /** Checks DKIM signatures of an incoming message (public key from the signer's DNS). */
+    public Verification verify(byte[] message) {
         try {
-            // Извлекаем заголовки для подписи
+            List<SignatureRecord> valid;
-            String from = extractHeader(mimeMessage, "From");
+            synchronized (verifier) { // DKIMVerifier keeps results between calls
-            String subject = extractHeader(mimeMessage, "Subject");
+                verifier.resetResults();
-            String date = extractHeader(mimeMessage, "Date");
+                valid = verifier.verify(new ByteArrayInputStream(message));
-            String to = extractHeader(mimeMessage, "To");
-            String messageId = extractHeader(mimeMessage, "Message-ID");
-
-            // Извлекаем тело сообщения
-            String body = extractBody(mimeMessage);
-
-            // Формируем канонизированное тело (relaxed канонизация)
-            String canonicalBody = canonicalizeBody(body);
-
-            // Формируем канонизированные заголовки
-            String headerCanonicalization = "r";
-            String bodyCanonicalization = "r";
-            String algorithm = "rsa-sha256";
-
-            // Строим заголовки для подписи
-            StringBuilder headersToSign = new StringBuilder();
-            String[] headerNames = {"from", "subject", "date", "to", "message-id"};
-            String[] headerValues = {from, subject, date, to, messageId};
-
-            for (int i = 0; i < headerNames.length; i++) {
-                headersToSign.append(headerNames[i]).append(":").append(headerValues[i]).append("\r\n");
             }
-
+            if (valid == null) {
-            // Вычисляем хэш тела
+                return Verification.NONE;
-            byte[] bodyHash = hashBody(canonicalBody);
+            }
-
+            if (valid.isEmpty()) {
-            // Формируем signing input
+                return new Verification(true, false, null);
-            String headerCanon = headersToSign.toString();
+            }
-            byte[] signingInput = (headerCanon + "bh=" + Base64.getEncoder().withoutPadding().encodeToString(bodyHash) + "\rbh=" + Base64.getEncoder().withoutPadding().encodeToString(bodyHash)).getBytes();
+            return new Verification(true, true, valid.get(0).getDToken().toString().toLowerCase(Locale.ROOT));
-
+        } catch (FailException e) {
-            // Подписываем
+            log.info("DKIM: signature failed: {}", e.getMessage());
-            Signature signature = Signature.getInstance("SHA256withRSA", "BC");
+            return new Verification(true, false, null);
-            signature.initSign(privateKey);
+        } catch (IOException e) {
-            signature.update(signingInput);
+            log.warn("DKIM: message cannot be read: {}", e.getMessage());
-            byte[] signatureBytes = signature.sign();
+            return new Verification(true, false, null);
-
-            // Формируем DKIM-Signature заголовок
-            String b64Signature = Base64.getEncoder().withoutPadding().encodeToString(signatureBytes);
-            String b64BodyHash = Base64.getEncoder().withoutPadding().encodeToString(bodyHash);
-
-            StringBuilder dkimHeader = new StringBuilder();
-            dkimHeader.append("v=1; ");
-            dkimHeader.append("a=").append(algorithm).append("; ");
-            dkimHeader.append("d=").append(domain).append("; ");
-            dkimHeader.append("s=").append(DKIM_SELECTOR).append("; ");
-            dkimHeader.append("c=").append(headerCanonicalization).append("/").append(bodyCanonicalization).append("; ");
-            dkimHeader.append("h=").append(String.join(":", headerNames)).append("; ");
-            dkimHeader.append("bh=").append(b64BodyHash).append("; ");
-            dkimHeader.append("b=").append(b64Signature);
-
-            mimeMessage.setHeader("DKIM-Signature", dkimHeader.toString());
-            log.debug("DKIM: сообщение подписано для домена {}", domain);
-
-        } catch (Exception e) {
-            log.error("DKIM: ошибка подписи сообщения", e);
-            // Не бросаем исключение — письмо будет отправлено без подписи
         }
     }
 
-    /**
+    static String domainOf(String address) {
-     * Верифицирует DKIM-подпись входящего сообщения.
+        int at = address == null ? -1 : address.lastIndexOf('@');
-     *
+        return at < 0 ? "" : address.substring(at + 1).toLowerCase(Locale.ROOT);
-     * @param mimeMessage MIME-сообщение с DKIM-подписью
+    }
-     * @return true если подпись валидна, false если подпись отсутствует или невалидна
-     */
-    public boolean verifyMessage(MimeMessage mimeMessage) {
-        if (!enabled) {
-            return true; // Если DKIM отключён, считаем все письма валидными
-        }
 
+    private static RSAPrivateKey readPrivateKey(String pem) throws IOException {
+        try (Reader reader = new StringReader(pem); PEMParser parser = new PEMParser(reader)) {
+            Object object = parser.readObject();
+            JcaPEMKeyConverter converter = new JcaPEMKeyConverter();
+            // PKCS#8 ("PRIVATE KEY") and the older PKCS#1 ("RSA PRIVATE KEY") written by earlier versions
+            if (object instanceof PEMKeyPair pair) {
+                return (RSAPrivateKey) converter.getKeyPair(pair).getPrivate();
+            }
+            if (object instanceof PrivateKeyInfo info) {
+                return (RSAPrivateKey) converter.getPrivateKey(info);
+            }
+            throw new IOException("Not an RSA private key: " + (object == null ? "empty file" : object.getClass().getSimpleName()));
+        }
+    }
+
+    private static byte[] publicKeyOf(RSAPrivateKey key) throws Exception {
+        RSAPrivateCrtKey crt = (RSAPrivateCrtKey) key;
+        return KeyFactory.getInstance("RSA")
+                .generatePublic(new RSAPublicKeySpec(crt.getModulus(), crt.getPublicExponent()))
+                .getEncoded();
+    }
+
+    private static void restrict(Path file) {
         try {
-            String dkimHeader = mimeMessage.getHeader("DKIM-Signature")[0];
+            Files.setPosixFilePermissions(file, PosixFilePermissions.fromString("rw-------"));
-            if (dkimHeader == null || dkimHeader.isEmpty()) {
+        } catch (UnsupportedOperationException | IOException ignored) {
-                log.debug("DKIM: подпись не найдена в сообщении");
+            // not a POSIX file system
-                return false;
-            }
-
-            // Извлекаем домен из подписи
-            String domain = extractDkimValue(dkimHeader, "d=");
-            if (domain == null || domain.isEmpty()) {
-                log.warn("DKIM: не удалось извлечь домен из подписи");
-                return false;
-            }
-
-            // В реальном мире здесь мы бы:
-            // 1. Сделали DNS-запрос для _domainkey.<domain>
-            // 2. Получили публичный ключ
-            // 3. Проверили подпись
-            //
-            // Для локального сервера мы проверяем, что подпись присутствует
-            // и имеет корректный формат
-            String version = extractDkimValue(dkimHeader, "v=");
-            String algorithm = extractDkimValue(dkimHeader, "a=");
-            String selector = extractDkimValue(dkimHeader, "s=");
-            String signature = extractDkimValue(dkimHeader, "b=");
-
-            if (version == null || !version.equals("1")) {
-                log.warn("DKIM: неверная версия подписи");
-                return false;
-            }
-
-            if (algorithm == null || !algorithm.startsWith("rsa-")) {
-                log.warn("DKIM: неподдерживаемый алгоритм: {}", algorithm);
-                return false;
-            }
-
-            if (signature == null || signature.isEmpty()) {
-                log.warn("DKIM: подпись пуста");
-                return false;
-            }
-
-            // Проверяем, что подпись — валидный Base64
-            try {
-                Base64.getDecoder().decode(signature);
-            } catch (IllegalArgumentException e) {
-                log.warn("DKIM: подпись не является валидным Base64");
-                return false;
-            }
-
-            log.info("DKIM: подпись найдена для домена {} (селектор: {})", domain, selector);
-
-            // Если письмо подписано нашим собственным ключом, проверяем полностью
-            if (domain.equals(this.domain) && privateKey != null) {
-                return verifyLocalSignature(mimeMessage, dkimHeader);
-            }
-
-            // Для внешних доменов проверяем только формат
-            return true;
-
-        } catch (Exception e) {
-            log.error("DKIM: ошибка верификации", e);
-            return false;
         }
     }
-
-    /**
-     * Верифицирует подпись локального домена.
-     */
-    private boolean verifyLocalSignature(MimeMessage mimeMessage, String dkimHeader) {
-        try {
-            String from = extractHeader(mimeMessage, "From");
-            String subject = extractHeader(mimeMessage, "Subject");
-            String date = extractHeader(mimeMessage, "Date");
-            String to = extractHeader(mimeMessage, "To");
-            String messageId = extractHeader(mimeMessage, "Message-ID");
-            String body = extractBody(mimeMessage);
-            String canonicalBody = canonicalizeBody(body);
-
-            StringBuilder headersToSign = new StringBuilder();
-            String[] headerNames = {"from", "subject", "date", "to", "message-id"};
-            String[] headerValues = {from, subject, date, to, messageId};
-
-            for (int i = 0; i < headerNames.length; i++) {
-                headersToSign.append(headerNames[i]).append(":").append(headerValues[i]).append("\r\n");
-            }
-
-            byte[] bodyHash = hashBody(canonicalBody);
-            String b64BodyHash = extractDkimValue(dkimHeader, "bh=");
-            String b64Signature = extractDkimValue(dkimHeader, "b=");
-
-            // Проверяем хэш тела
-            if (b64BodyHash != null) {
-                byte[] claimedBodyHash = Base64.getDecoder().decode(b64BodyHash);
-                if (!MessageDigest.isEqual(bodyHash, claimedBodyHash)) {
-                    log.warn("DKIM: хэш тела не совпадает");
-                    return false;
-                }
-            }
-
-            // Проверяем подпись
-            String headerCanon = headersToSign.toString();
-            byte[] signingInput = (headerCanon + "bh=" + b64BodyHash + "\rbh=" + b64BodyHash).getBytes();
-
-            Signature signature = Signature.getInstance("SHA256withRSA", "BC");
-            signature.initVerify(publicKey);
-            signature.update(signingInput);
-
-            byte[] signatureBytes = Base64.getDecoder().decode(b64Signature);
-            boolean valid = signature.verify(signatureBytes);
-
-            if (valid) {
-                log.info("DKIM: подпись локального домена верифицирована");
-            } else {
-                log.warn("DKIM: подпись локального домена не верифицирована");
-            }
-
-            return valid;
-
-        } catch (Exception e) {
-            log.error("DKIM: ошибка верификации локальной подписи", e);
-            return false;
-        }
-    }
-
-    /**
-     * Извлекает значение параметра из DKIM-заголовка.
-     */
-    private String extractDkimValue(String dkimHeader, String param) {
-        int index = dkimHeader.indexOf(param);
-        if (index == -1) return null;
-
-        int start = index + param.length();
-        int end = dkimHeader.indexOf(";", start);
-        if (end == -1) end = dkimHeader.length();
-
-        return dkimHeader.substring(start, end).trim();
-    }
-
-    /**
-     * Извлекает заголовок из MIME-сообщения.
-     */
-    private String extractHeader(MimeMessage mimeMessage, String name) throws MessagingException {
-        String[] headers = mimeMessage.getHeader(name);
-        if (headers == null || headers.length == 0) return "";
-        return headers[0];
-    }
-
-    /**
-     * Извлекает тело MIME-сообщения.
-     */
-    private String extractBody(MimeMessage mimeMessage) throws MessagingException, IOException {
-        Object content = mimeMessage.getContent();
-        if (content instanceof String) {
-            return (String) content;
-        } else if (content instanceof jakarta.mail.internet.MimeMultipart) {
-            jakarta.mail.internet.MimeMultipart multipart = (jakarta.mail.internet.MimeMultipart) content;
-            StringBuilder body = new StringBuilder();
-            for (int i = 0; i < multipart.getCount(); i++) {
-                var part = multipart.getBodyPart(i);
-                String contentType = part.getContentType();
-                if (contentType != null && contentType.toLowerCase().contains("text")) {
-                    Object partContent = part.getContent();
-                    if (partContent instanceof String) {
-                        body.append(partContent);
-                    }
-                }
-            }
-            return body.toString();
-        }
-        return "";
-    }
-
-    /**
-     * Канонизация тела сообщения (relaxed канонизация).
-     * Убирает лишние пробелы и переводы строк.
-     */
-    private String canonicalizeBody(String body) {
-        if (body == null) return "";
-        // Relaxed: нормализуем CRLF в LF, убираем пробелы в конце строк
-        return body.replaceAll("\\r\\n", "\n")
-                   .replaceAll("\\r", "\n")
-                   .replaceAll(" +\n", "\n")
-                   .replaceAll("\n+", "\n")
-                   .trim();
-    }
-
-    /**
-     * Вычисляет SHA-256 хэш тела сообщения.
-     */
-    private byte[] hashBody(String body) throws NoSuchAlgorithmException {
-        MessageDigest digest = MessageDigest.getInstance("SHA-256");
-        return digest.digest(body.getBytes());
-    }
-
-    /**
-     * Возвращает публичный ключ в формате DNS TXT-записи.
-     * Используется для публикации в DNS.
-     */
-    public String getPublicKeyForDns() {
-        if (publicKeyBase64 == null) return null;
-        return "v=DKIM1; k=rsa; p=" + publicKeyBase64;
-    }
-
-    /**
-     * Возвращает домен DKIM.
-     */
-    public String getDomain() {
-        return domain;
-    }
-
-    /**
-     * Возвращает селектор DKIM.
-     */
-    public String getSelector() {
-        return DKIM_SELECTOR;
-    }
 }

backend/src/main/java/com/mailserver/service/LocalDelivery.java

@@ -0,0 +1,192 @@
+package com.mailserver.service;
+
+import com.mailserver.delivery.DeliveryWorker;
+import com.mailserver.delivery.OutboundMessage;
+import jakarta.mail.BodyPart;
+import jakarta.mail.MessagingException;
+import jakarta.mail.Multipart;
+import jakarta.mail.Part;
+import jakarta.mail.Session;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import jakarta.mail.internet.MimeUtility;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+
+/**
+ * Stores a message in one of our mailboxes. Mail from outside is checked first — DKIM (signature),
+ * SPF (the connecting IP against the envelope sender's domain), DMARC (policy of the From domain);
+ * a failure marks it as spam. Mail from our own logged-in users is trusted.
+ */
+@Service
+public class LocalDelivery implements DeliveryWorker.BounceSender {
+
+    private static final Logger log = LoggerFactory.getLogger(LocalDelivery.class);
+
+    private final MailService mailService;
+    private final DkimService dkimService;
+    private final SpfService spfService;
+    private final DmarcService dmarcService;
+    private final String hostname;
+    private final MessageSources sources;
+
+    public LocalDelivery(MailService mailService, DkimService dkimService, SpfService spfService,
+                         DmarcService dmarcService, @Value("${mailserver.smtp.hostname:localhost}") String hostname,
+                         MessageSources sources) {
+        this.sources = sources;
+        this.mailService = mailService;
+        this.dkimService = dkimService;
+        this.spfService = spfService;
+        this.dmarcService = dmarcService;
+        this.hostname = hostname;
+    }
+
+    /** Blocking: call from a worker thread. */
+    public void deliver(byte[] raw, String mailbox, String remoteIp, String envelopeFrom, boolean trusted)
+            throws MessagingException, IOException {
+        MimeMessage mime = new MimeMessage(Session.getInstance(new Properties()), new ByteArrayInputStream(raw));
+
+        String senderEmail = envelopeFrom;
+        String senderName = null;
+        if (mime.getFrom() != null && mime.getFrom().length > 0 && mime.getFrom()[0] instanceof InternetAddress from) {
+            senderEmail = from.getAddress();
+            senderName = from.getPersonal();
+        }
+        String subject = mime.getSubject() == null ? "" : mime.getSubject();
+        Body body = body(mime);
+
+        boolean spam = false;
+        if (!trusted) {
+            DkimService.Verification dkim = dkimService.verify(raw);
+            String spfSender = envelopeFrom == null || envelopeFrom.isEmpty() ? senderEmail : envelopeFrom;
+            SpfService.SpfResult spf = spfService.checkSpf(spfSender, remoteIp);
+            boolean spfPassed = spf == SpfService.SpfResult.PASS;
+            DmarcService.DmarcResult dmarc = dmarcService.checkDmarc(senderEmail, remoteIp, spfPassed, dkim.passed(), dkim.domain());
+            spam = dmarcService.shouldMarkAsSpam(dmarc) || spf == SpfService.SpfResult.FAIL || (dkim.signed() && !dkim.passed());
+            log.info("Incoming {} -> {} from {}: DKIM {}, SPF {}, DMARC {}{}", senderEmail, mailbox, remoteIp,
+                    dkim.signed() ? (dkim.passed() ? "pass " + dkim.domain() : "fail") : "none", spf, dmarc, spam ? " → spam" : "");
+        }
+
+        com.mailserver.domain.Message stored =
+                mailService.receiveMessage(senderEmail, senderName, mailbox, subject, body.text(), body.html(), spam,
+                        addresses(mime, jakarta.mail.Message.RecipientType.TO),
+                        addresses(mime, jakarta.mail.Message.RecipientType.CC)).block();
+        if (stored != null) {
+            for (FilePart file : attachments(mime)) {
+                mailService.storeIncomingAttachment(stored.getId(), file.name(), file.contentType(), file.bytes());
+            }
+            // IMAP serves the message exactly as it arrived
+            sources.put(stored.getId(), raw).block();
+        }
+    }
+
+    /** "a@x, b@y" from a header, or null. A broken header is ignored, not a reason to lose the message. */
+    public static String addresses(MimeMessage mime, jakarta.mail.Message.RecipientType type) {
+        try {
+            jakarta.mail.Address[] list = mime.getRecipients(type);
+            if (list == null || list.length == 0) {
+                return null;
+            }
+            List<String> result = new ArrayList<>();
+            for (jakarta.mail.Address address : list) {
+                result.add(address instanceof InternetAddress internet ? internet.getAddress() : address.toString());
+            }
+            String joined = String.join(", ", result);
+            return joined.length() > 5000 ? joined.substring(0, 5000) : joined;
+        } catch (MessagingException e) {
+            return null;
+        }
+    }
+
+    public record FilePart(String name, String contentType, byte[] bytes) {
+    }
+
+    /** Parts with a file name (attachments and inline images), nested multiparts walked. */
+    public static List<FilePart> attachments(Part part) throws MessagingException, IOException {
+        List<FilePart> files = new ArrayList<>();
+        collect(part, files);
+        return files;
+    }
+
+    private static void collect(Part part, List<FilePart> files) throws MessagingException, IOException {
+        if (part.isMimeType("multipart/*") && part.getContent() instanceof Multipart multipart) {
+            for (int i = 0; i < multipart.getCount(); i++) {
+                collect(multipart.getBodyPart(i), files);
+            }
+            return;
+        }
+        String name = part.getFileName();
+        if (name == null && !Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition())) {
+            return;
+        }
+        String decoded = name == null ? "file" : MimeUtility.decodeText(name);
+        String type = part.getContentType() == null ? "application/octet-stream" : part.getContentType().split(";")[0].trim();
+        try (InputStream in = part.getInputStream()) {
+            files.add(new FilePart(decoded, type.toLowerCase(java.util.Locale.ROOT), in.readAllBytes()));
+        }
+    }
+
+    /** Non-delivery report into the sender's inbox — only when the sender is our mailbox. */
+    @Override
+    public void bounce(OutboundMessage message, String reason) {
+        String text = "Your message to " + message.getRcptTo() + " could not be delivered.\n\n"
+                + "Reason: " + reason + "\n\nAttempts: " + message.getAttempts() + "\n";
+        try {
+            mailService.receiveMessage("mailer-daemon@" + hostname, "Mail Delivery System", message.getMailFrom(),
+                    "Undelivered: message to " + message.getRcptTo(), text, false, false).block();
+        } catch (IllegalArgumentException notOurs) {
+            log.info("Bounce not stored: sender {} is not a local mailbox", message.getMailFrom());
+        }
+    }
+
+    public record Body(String text, boolean html) {
+    }
+
+    /** HTML part when the message has one, otherwise the plain text; nested multiparts are walked. */
+    public static Body body(Part part) throws MessagingException, IOException {
+        String html = find(part, "text/html");
+        if (html != null) {
+            return new Body(html, true);
+        }
+        String plain = find(part, "text/plain");
+        return new Body(plain == null ? "" : plain, false);
+    }
+
+    private static String find(Part part, String type) throws MessagingException, IOException {
+        if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition()) || part.getFileName() != null) {
+            return null;
+        }
+        if (part.isMimeType(type)) {
+            Object content = part.getContent();
+            if (content instanceof String s) {
+                return s;
+            }
+            if (content instanceof InputStream in) {
+                try (in) {
+                    return new String(in.readAllBytes(), StandardCharsets.UTF_8);
+                }
+            }
+            return null;
+        }
+        if (part.isMimeType("multipart/*") && part.getContent() instanceof Multipart multipart) {
+            for (int i = 0; i < multipart.getCount(); i++) {
+                BodyPart child = multipart.getBodyPart(i);
+                String found = find(child, type);
+                if (found != null) {
+                    return found;
+                }
+            }
+        }
+        return null;
+    }
+}

backend/src/main/java/com/mailserver/service/MailService.java

@@ -6,8 +6,10 @@ import com.mailserver.domain.Folder;
 import com.mailserver.domain.Message;
 import com.mailserver.domain.User;
 import com.mailserver.dto.AttachmentResponse;
+import com.mailserver.dto.DraftRequest;
+import com.mailserver.dto.FolderResponse;
+import com.mailserver.dto.MessageUpdateRequest;
 import com.mailserver.dto.MessageResponse;
-import com.mailserver.dto.SendRequest;
 import com.mailserver.repository.AttachmentRepository;
 import com.mailserver.repository.ContactRepository;
 import com.mailserver.repository.FolderRepository;
@@ -15,16 +17,14 @@ import com.mailserver.repository.MessageRepository;
 import com.mailserver.repository.UserRepository;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import jakarta.mail.MessagingException;
-import jakarta.mail.Session;
-import jakarta.mail.internet.MimeMessage;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
+import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Service;
+import org.springframework.web.server.ResponseStatusException;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.publisher.Sinks;
 
 import java.io.*;
 import java.nio.charset.StandardCharsets;
@@ -33,11 +33,11 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.Locale;
 import java.util.List;
 import java.util.Properties;
 import java.util.UUID;
-import reactor.netty.Connection;
-import reactor.netty.tcp.TcpClient;
 
 @Service
 public class MailService {
@@ -50,113 +50,251 @@ public class MailService {
     private final AttachmentRepository attachmentRepository;
     private final ContactRepository contactRepository;
     private final SpamFilterService spamFilterService;
-    private final DkimService dkimService;
 
     @Value("${mailserver.attachments.dir:./attachments}")
     private String attachmentsDir;
 
-    @Value("${mailserver.smtp.port:3025}")
-    private int smtpPort;
 
-    @Value("${mailserver.smtp.hostname:localhost}")
-    private String smtpHostname;
 
     public MailService(MessageRepository messageRepository, FolderRepository folderRepository,
                        UserRepository userRepository, AttachmentRepository attachmentRepository,
                        ContactRepository contactRepository,
-                       SpamFilterService spamFilterService,
+                       SpamFilterService spamFilterService, MessageSources sources) {
-                       DkimService dkimService) {
+        this.sources = sources;
         this.messageRepository = messageRepository;
         this.folderRepository = folderRepository;
         this.userRepository = userRepository;
         this.attachmentRepository = attachmentRepository;
         this.contactRepository = contactRepository;
         this.spamFilterService = spamFilterService;
-        this.dkimService = dkimService;
     }
 
-    public Mono<MessageResponse> sendMessage(String fromEmail, SendRequest request) {
+    /** System folders in the order the web client shows them; the rest — own folders, by name. */
-        return userRepository.findByEmail(fromEmail)
+    private final MessageSources sources;
-                .switchIfEmpty(Mono.error(new IllegalArgumentException("Sender not found: " + fromEmail)))
+
-                .flatMap(fromUser ->
+    public static final List<String> SYSTEM_FOLDERS = List.of("INBOX", "Drafts", "Sent", "Spam", "Trash");
-                    folderRepository.findByUserIdAndName(fromUser.getId(), "Sent")
+
-                        .switchIfEmpty(Mono.error(new IllegalStateException("Sent folder not found")))
+    /** Messages per folder in one list — the web client sorts and pages them itself. */
-                        .flatMap(sentFolder -> {
+    public static final int LIST_LIMIT = 1000;
-                            Message message = new Message();
+
-                            message.setFolderId(sentFolder.getId());
+    private static final int PREVIEW_CHARS = 200;
-                            message.setSenderEmail(fromEmail);
+
-                            message.setSenderName(fromUser.getDisplayName());
+    // --- Folders ---
-                            message.setRecipientEmail(request.getTo());
+
-                            message.setSubject(request.getSubject());
+    public Flux<FolderResponse> folders(Long userId) {
-                            message.setBody(request.getBody());
+        return folderRepository.findByUserId(userId)
-                            message.setHtml(request.isHtml());
+                .flatMap(folder -> Mono.zip(messageRepository.countByFolderId(folder.getId()),
-                            message.setRead(true);
+                                messageRepository.countUnreadByFolderId(folder.getId()))
-                            message.setReceivedAt(Instant.now());
+                        .map(counts -> new FolderResponse(folder.getId(), folder.getName(), folder.isSystem(),
-                            message.setMessageId(UUID.randomUUID().toString());
+                                counts.getT1(), counts.getT2())))
-                            message.setMessageSize((long) (request.getSubject().length() + request.getBody().length()));
+                .sort(Comparator.comparingInt(MailService::folderOrder)
-                            return messageRepository.save(message);
+                        .thenComparing(folder -> folder.name().toLowerCase(Locale.ROOT)));
-                        })
-                        .flatMap(message ->
-                            sendViaSmtp(fromEmail, request.getTo(), request.getSubject(), request.getBody(),
-                                    request.isHtml(), message.getMessageId())
-                                    .doOnSuccess(v -> log.info("Email sent via SMTP: {} -> {}", fromEmail, request.getTo()))
-                                    .onErrorResume(e -> {
-                                        log.error("SMTP send failed: {}", e.getMessage(), e);
-                                        return Mono.empty();
-                                    })
-                                    .thenReturn(message)
-                        )
-                        .map(this::toResponse)
-                );
     }
 
-    public Mono<Void> receiveMessage(String senderEmail, String senderName, String recipientEmail,
+    private static int folderOrder(FolderResponse folder) {
+        int index = SYSTEM_FOLDERS.indexOf(folder.name());
+        return folder.system() && index >= 0 ? index : SYSTEM_FOLDERS.size();
+    }
+
+    public Mono<FolderResponse> createFolder(Long userId, String rawName) {
+        String name = folderName(rawName);
+        return checkFolderNameFree(userId, name, null)
+                .then(Mono.defer(() -> {
+                    Folder folder = new Folder();
+                    folder.setUserId(userId);
+                    folder.setName(name);
+                    folder.setCreatedAt(Instant.now());
+                    return folderRepository.save(folder);
+                }))
+                .map(folder -> new FolderResponse(folder.getId(), folder.getName(), false, 0, 0));
+    }
+
+    public Mono<Void> renameFolder(Long folderId, Long userId, String rawName) {
+        String name = folderName(rawName);
+        return ownFolder(folderId, userId)
+                .flatMap(folder -> checkFolderNameFree(userId, name, folder.getId())
+                        .then(Mono.defer(() -> {
+                            folder.setName(name);
+                            return folderRepository.save(folder);
+                        })))
+                .then();
+    }
+
+    /** An own folder: its messages go to the Trash, then the folder is removed. */
+    public Mono<Void> deleteFolder(Long folderId, Long userId) {
+        return ownFolder(folderId, userId)
+                .flatMap(folder -> systemFolder(userId, "Trash")
+                        .flatMap(trash -> messageRepository.moveAll(folder.getId(), trash.getId()))
+                        .then(folderRepository.delete(folder)));
+    }
+
+    /** Trash and Spam only: removes every message for good. */
+    public Mono<Integer> emptyFolder(Long folderId, Long userId) {
+        return ownedFolder(folderId, userId)
+                .filter(folder -> folder.isSystem() && ("Trash".equals(folder.getName()) || "Spam".equals(folder.getName())))
+                .switchIfEmpty(Mono.error(badRequest("Only Trash and Spam can be emptied")))
+                .flatMapMany(folder -> messageRepository.findByFolderId(folder.getId()))
+                .concatMap(message -> purge(message).thenReturn(1))
+                .reduce(0, Integer::sum);
+    }
+
+    private static String folderName(String rawName) {
+        String name = rawName == null ? "" : rawName.trim().replaceAll("\\s+", " ");
+        if (name.isEmpty() || name.length() > 50) {
+            throw badRequest("Folder name: 1 to 50 characters");
+        }
+        if (SYSTEM_FOLDERS.stream().anyMatch(name::equalsIgnoreCase)) {
+            throw badRequest("This name belongs to a system folder");
+        }
+        return name;
+    }
+
+    private Mono<Void> checkFolderNameFree(Long userId, String name, Long exceptId) {
+        return folderRepository.findByUserId(userId)
+                .filter(folder -> folder.getName().equalsIgnoreCase(name) && !folder.getId().equals(exceptId))
+                .hasElements()
+                .flatMap(taken -> taken ? Mono.error(badRequest("A folder with this name already exists")) : Mono.empty());
+    }
+
+    private Mono<Folder> ownFolder(Long folderId, Long userId) {
+        return ownedFolder(folderId, userId)
+                .filter(folder -> !folder.isSystem())
+                .switchIfEmpty(Mono.error(badRequest("System folders cannot be renamed or deleted")));
+    }
+
+    private Mono<Folder> systemFolder(Long userId, String name) {
+        return folderRepository.findByUserIdAndName(userId, name)
+                .switchIfEmpty(Mono.error(new IllegalStateException(name + " folder not found")));
+    }
+
+    // --- Messages ---
+
+    /** Copy of a message we sent, in the sender's "Sent" folder. */
+    public Mono<Message> saveSent(User fromUser, String to, String cc, String subject, String body, boolean html, String messageId) {
+        return systemFolder(fromUser.getId(), "Sent")
+                .flatMap(sentFolder -> {
+                    Message message = new Message();
+                    message.setFolderId(sentFolder.getId());
+                    message.setSenderEmail(fromUser.getEmail());
+                    message.setSenderName(fromUser.getDisplayName());
+                    message.setRecipientEmail(to);
+                    message.setCcEmail(cc == null || cc.isBlank() ? null : cc);
+                    message.setSubject(subject);
+                    message.setBody(body);
+                    message.setHtml(html);
+                    message.setRead(true);
+                    message.setReceivedAt(Instant.now());
+                    message.setMessageId(messageId);
+                    message.setMessageSize((long) (subject.length() + body.length()));
+                    return messageRepository.save(message);
+                });
+    }
+
+    /** Creates or updates a draft of the user (only a message in their Drafts folder can be updated). */
+    public Mono<MessageResponse> saveDraft(User user, Long draftId, DraftRequest request) {
+        Mono<Message> target = draftId == null
+                ? systemFolder(user.getId(), "Drafts").map(drafts -> {
+                    Message message = new Message();
+                    message.setFolderId(drafts.getId());
+                    message.setRead(true);
+                    message.setMessageId(UUID.randomUUID().toString());
+                    return message;
+                })
+                : ownedDraft(draftId, user.getId());
+        return target.flatMap(message -> {
+                    String subject = request.subject() == null ? "" : request.subject();
+                    String body = request.body() == null ? "" : request.body();
+                    message.setSenderEmail(user.getEmail());
+                    message.setSenderName(user.getDisplayName());
+                    message.setRecipientEmail(request.to() == null ? "" : request.to().trim());
+                    message.setCcEmail(request.cc() == null || request.cc().isBlank() ? null : request.cc().trim());
+                    message.setSubject(subject);
+                    message.setBody(body);
+                    message.setHtml(request.html());
+                    message.setReceivedAt(Instant.now());
+                    message.setMessageSize((long) (subject.length() + body.length()));
+                    return messageRepository.save(message);
+                })
+                // IMAP: the draft changed — its MIME text is built anew
+                .flatMap(saved -> sources.remove(saved.getId()).thenReturn(saved))
+                .flatMap(this::withAttachmentCount);
+    }
+
+    /** The user's draft, or 404. */
+    public Mono<Message> ownedDraft(Long draftId, Long userId) {
+        return ownedMessage(draftId, userId)
+                .filterWhen(message -> folderRepository.findById(message.getFolderId())
+                        .map(folder -> folder.isSystem() && "Drafts".equals(folder.getName())))
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND, "Draft not found")));
+    }
+
+    /** After sending: the draft's attachments move to the copy in Sent, the draft itself is removed. */
+    public Mono<Void> finishDraft(Long draftId, Long sentMessageId) {
+        return attachmentRepository.moveAll(draftId, sentMessageId)
+                .then(sources.remove(sentMessageId))
+                .then(messageRepository.deleteById(draftId));
+    }
+
+    public Mono<Message> receiveMessage(String senderEmail, String senderName, String recipientEmail,
                                String subject, String body, boolean isHtml) {
         return receiveMessage(senderEmail, senderName, recipientEmail, subject, body, isHtml, false);
     }
 
-    public Mono<Void> receiveMessage(String senderEmail, String senderName, String recipientEmail,
+    public Mono<Message> receiveMessage(String senderEmail, String senderName, String recipientEmail,
                                String subject, String body, boolean isHtml, boolean externalSpamFlag) {
-        return userRepository.findByEmail(recipientEmail)
+        return receiveMessage(senderEmail, senderName, recipientEmail, subject, body, isHtml, externalSpamFlag, null, null);
-                .switchIfEmpty(Mono.error(new IllegalArgumentException("Recipient not found: " + recipientEmail)))
-                .flatMap(recipient ->
-                    folderRepository.findByUserIdAndName(recipient.getId(), "INBOX")
-                        .switchIfEmpty(Mono.error(new IllegalStateException("INBOX not found")))
-                        .flatMap(inbox ->
-                            spamFilterService.isBlacklisted(recipient.getId(), senderEmail)
-                                .flatMap(isBlacklisted -> {
-                                    boolean isSpam = isBlacklisted || externalSpamFlag;
-                                    Message message = new Message();
-                                    message.setFolderId(inbox.getId());
-                                    message.setSenderEmail(senderEmail);
-                                    message.setSenderName(senderName);
-                                    message.setRecipientEmail(recipientEmail);
-                                    message.setSubject(subject);
-                                    message.setBody(body);
-                                    message.setHtml(isHtml);
-                                    message.setRead(false);
-                                    message.setSpam(isSpam);
-                                    message.setReceivedAt(Instant.now());
-                                    message.setMessageId(UUID.randomUUID().toString());
-                                    message.setMessageSize((long) (subject.length() + body.length()));
-                                    return messageRepository.save(message)
-                                        .then(folderRepository.save(inbox));
-                                })
-                        )
-                )
-                .then();
     }
 
-    public Flux<MessageResponse> getMessages(Long folderId, Long userId, int page, int size) {
+    /**
-        PageRequest pageable = PageRequest.of(page, size, Sort.by(Sort.Direction.DESC, "receivedAt"));
+     * Stores an incoming message: into INBOX, or into Spam when it failed the checks or the sender is blacklisted.
-        return messageRepository.findByFolderId(folderId, pageable)
+     * {@code toHeader}/{@code ccHeader}: addresses from the message headers (shown, used by "reply all");
-                .map(this::toResponse);
+     * without them — the mailbox itself.
+     */
+    public Mono<Message> receiveMessage(String senderEmail, String senderName, String recipientEmail,
+                               String subject, String body, boolean isHtml, boolean externalSpamFlag,
+                               String toHeader, String ccHeader) {
+        return userRepository.findByEmail(recipientEmail)
+                .switchIfEmpty(Mono.error(new IllegalArgumentException("Recipient not found: " + recipientEmail)))
+                .flatMap(recipient -> spamFilterService.isBlacklisted(recipient.getId(), senderEmail)
+                        .flatMap(blacklisted -> {
+                            boolean isSpam = blacklisted || externalSpamFlag;
+                            return systemFolder(recipient.getId(), isSpam ? "Spam" : "INBOX")
+                                    .flatMap(folder -> {
+                                        Message message = new Message();
+                                        message.setFolderId(folder.getId());
+                                        message.setSenderEmail(senderEmail);
+                                        message.setSenderName(senderName);
+                                        message.setRecipientEmail(toHeader == null || toHeader.isBlank() ? recipientEmail : toHeader);
+                                        message.setCcEmail(ccHeader == null || ccHeader.isBlank() ? null : ccHeader);
+                                        message.setSubject(subject);
+                                        message.setBody(body);
+                                        message.setHtml(isHtml);
+                                        message.setRead(false);
+                                        message.setSpam(isSpam);
+                                        message.setReceivedAt(Instant.now());
+                                        message.setMessageId(UUID.randomUUID().toString());
+                                        message.setMessageSize((long) (subject.length() + body.length()));
+                                        return messageRepository.save(message);
+                                    });
+                        }));
+    }
+
+    /** Newest first; bodies cut to a preview — the full message comes from {@link #getMessage}. */
+    public Flux<MessageResponse> listMessages(Long folderId, Long userId, int limit) {
+        int safeLimit = Math.max(1, Math.min(limit, LIST_LIMIT));
+        return ownedFolder(folderId, userId)
+                .flatMapMany(folder -> messageRepository.findLatest(folder.getId(), safeLimit))
+                .concatMap(this::withAttachmentCount)
+                .map(MailService::preview);
     }
 
     public Flux<MessageResponse> searchMessages(Long folderId, Long userId, String keyword, int page, int size) {
         PageRequest pageable = PageRequest.of(page, size, Sort.by(Sort.Direction.DESC, "receivedAt"));
-        return messageRepository.searchInFolder(folderId, keyword, pageable)
+        return ownedFolder(folderId, userId)
-                .map(this::toResponse);
+                .flatMapMany(folder -> messageRepository.searchInFolder(folder.getId(), keyword, pageable))
+                .take(LIST_LIMIT)
+                .concatMap(this::withAttachmentCount)
+                .map(MailService::preview);
     }
 
     public Flux<MessageResponse> searchMessagesWithFilters(Long folderId, Long userId,
@@ -164,25 +302,125 @@ public class MailService {
                                                            String sender, String recipient,
                                                            int page, int size) {
         PageRequest pageable = PageRequest.of(page, size, Sort.by(Sort.Direction.DESC, "receivedAt"));
-        return messageRepository.searchWithFilters(folderId, subject, body, sender, recipient, pageable)
+        return ownedFolder(folderId, userId)
-                .map(this::toResponse);
+                .flatMapMany(folder -> messageRepository.searchWithFilters(folder.getId(), subject, body, sender, recipient, pageable))
+                .take(LIST_LIMIT)
+                .concatMap(this::withAttachmentCount)
+                .map(MailService::preview);
     }
 
     public Mono<MessageResponse> getMessage(Long messageId, Long userId) {
-        return messageRepository.findById(messageId)
+        return ownedMessage(messageId, userId).flatMap(this::withAttachmentCount);
-                .map(this::toResponse);
     }
 
     public Mono<Void> markAsRead(Long messageId, Long userId) {
-        return messageRepository.findById(messageId)
+        return updateMessage(messageId, userId, new MessageUpdateRequest(true, null, null)).then();
+    }
+
+    /** Read/unread, flag, move to another folder of the user (moving into Spam marks it as spam, out of it — not). */
+    public Mono<MessageResponse> updateMessage(Long messageId, Long userId, MessageUpdateRequest update) {
+        return ownedMessage(messageId, userId)
                 .flatMap(message -> {
-                    message.setRead(true);
+                    if (update.read() != null) {
-                    return messageRepository.save(message).then();
+                        message.setRead(update.read());
+                    }
+                    if (update.flagged() != null) {
+                        message.setFlagged(update.flagged());
+                    }
+                    if (update.folderId() == null || update.folderId().equals(message.getFolderId())) {
+                        return messageRepository.save(message);
+                    }
+                    return ownedFolder(update.folderId(), userId).flatMap(target -> {
+                        message.setFolderId(target.getId());
+                        message.setSpam(target.isSystem() && "Spam".equals(target.getName()));
+                        return messageRepository.save(message);
+                    });
+                })
+                .flatMap(this::withAttachmentCount);
+    }
+
+    /** Into the Trash; a message already in the Trash is removed for good (with its attachment files). */
+    public Mono<Void> deleteMessage(Long messageId, Long userId) {
+        return ownedMessage(messageId, userId)
+                .flatMap(message -> folderRepository.findById(message.getFolderId())
+                        .flatMap(folder -> {
+                            if (folder.isSystem() && "Trash".equals(folder.getName())) {
+                                return purge(message);
+                            }
+                            return systemFolder(userId, "Trash").flatMap(trash -> {
+                                message.setFolderId(trash.getId());
+                                return messageRepository.save(message).then();
+                            });
+                        }));
+    }
+
+    private Mono<Void> purge(Message message) {
+        return attachmentRepository.findByMessageId(message.getId())
+                .doOnNext(attachment -> deleteFile(attachment.getFilePath()))
+                .then(messageRepository.delete(message));
+    }
+
+    private static void deleteFile(String path) {
+        try {
+            Files.deleteIfExists(Paths.get(path));
+        } catch (IOException e) {
+            log.warn("Attachment file {} not deleted: {}", path, e.getMessage());
+        }
+    }
+
+    /** Bytes used by the mailbox: message texts plus attachments. */
+    public Mono<Long> usedBytes(Long userId) {
+        return Mono.zip(messageRepository.sumSizeByUserId(userId), attachmentRepository.sumSizeByUserId(userId))
+                .map(sizes -> sizes.getT1() + sizes.getT2());
+    }
+
+    /** The folder, when it belongs to the user; otherwise 404 — never someone else's mail. */
+    private Mono<Folder> ownedFolder(Long folderId, Long userId) {
+        return folderRepository.findById(folderId)
+                .filter(folder -> folder.getUserId().equals(userId))
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND, "Folder not found")));
+    }
+
+    private Mono<Message> ownedMessage(Long messageId, Long userId) {
+        return messageRepository.findById(messageId)
+                .filterWhen(message -> folderRepository.findById(message.getFolderId())
+                        .map(folder -> folder.getUserId().equals(userId))
+                        .defaultIfEmpty(false))
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND, "Message not found")));
+    }
+
+    private Mono<Attachment> ownedAttachment(Long attachmentId, Long userId) {
+        return attachmentRepository.findById(attachmentId)
+                .filterWhen(attachment -> ownedMessage(attachment.getMessageId(), userId).hasElement()
+                        .onErrorReturn(false))
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND, "Attachment not found")));
+    }
+
+    private Mono<MessageResponse> withAttachmentCount(Message message) {
+        return attachmentRepository.countByMessageId(message.getId())
+                .defaultIfEmpty(0L)
+                .map(count -> {
+                    MessageResponse response = toResponse(message);
+                    response.setAttachmentCount(count.intValue());
+                    response.setHasAttachments(count > 0);
+                    return response;
                 });
     }
 
-    public Mono<Void> deleteMessage(Long messageId, Long userId) {
+    private static MessageResponse preview(MessageResponse response) {
-        return messageRepository.deleteById(messageId);
+        String body = response.getBody();
+        if (body == null) {
+            return response;
+        }
+        String text = response.isHtml() ? body.replaceAll("(?s)<style.*?</style>|<[^>]+>", " ") : body;
+        text = text.replace("&nbsp;", " ").replaceAll("\\s+", " ").trim();
+        response.setBody(text.length() > PREVIEW_CHARS ? text.substring(0, PREVIEW_CHARS) + "…" : text);
+        response.setHtml(false);
+        return response;
+    }
+
+    static ResponseStatusException badRequest(String reason) {
+        return new ResponseStatusException(HttpStatus.BAD_REQUEST, reason);
     }
 
     private MessageResponse toResponse(Message message) {
@@ -191,6 +429,7 @@ public class MailService {
         resp.setSenderEmail(message.getSenderEmail());
         resp.setSenderName(message.getSenderName());
         resp.setRecipientEmail(message.getRecipientEmail());
+        resp.setCcEmail(message.getCcEmail());
         resp.setSubject(message.getSubject());
         resp.setBody(message.getBody());
         resp.setHtml(message.isHtml());
@@ -203,10 +442,30 @@ public class MailService {
         return resp;
     }
 
+    /** Stores a file of an incoming message (blocking: called from the SMTP worker thread). */
+    public void storeIncomingAttachment(Long messageId, String filename, String contentType, byte[] bytes) throws IOException {
+        String safeName = com.mailserver.controller.MailController.safeFilename(filename);
+        Path path = Paths.get(attachmentsDir, UUID.randomUUID() + "_" + safeName);
+        Files.createDirectories(path.getParent());
+        Files.write(path, bytes);
+        Attachment attachment = new Attachment();
+        attachment.setMessageId(messageId);
+        attachment.setFilename(safeName);
+        attachment.setContentType(contentType);
+        attachment.setSizeBytes((long) bytes.length);
+        attachment.setFilePath(path.toString());
+        attachmentRepository.save(attachment).block();
+    }
+
+    /** Attachments of the user's draft, for building the message to send. */
+    public Flux<Attachment> draftAttachments(Long draftId, Long userId) {
+        return ownedDraft(draftId, userId).flatMapMany(draft -> attachmentRepository.findByMessageId(draft.getId()));
+    }
+
     public Mono<AttachmentResponse> saveAttachmentReactive(Long messageId, Long userId,
                                                      String originalFilename, String contentType,
                                                      long sizeBytes, String filePath) {
-        return messageRepository.findById(messageId)
+        return ownedDraft(messageId, userId)
                 .flatMap(message -> {
                     Attachment attachment = new Attachment();
                     attachment.setMessageId(messageId);
@@ -214,7 +473,7 @@ public class MailService {
                     attachment.setContentType(contentType);
                     attachment.setSizeBytes(sizeBytes);
                     attachment.setFilePath(filePath);
-                    return attachmentRepository.save(attachment);
+                    return sources.remove(messageId).then(attachmentRepository.save(attachment));
                 })
                 .map(this::toAttachmentResponse);
     }
@@ -223,32 +482,22 @@ public class MailService {
         return attachmentsDir;
     }
 
-    public String getAttachmentFilePath(Long attachmentId, Long userId) {
+    /** The attachment record (file path, name, type) — only the owner's. */
-        return attachmentRepository.findById(attachmentId)
+    public Mono<Attachment> getAttachment(Long attachmentId, Long userId) {
-                .map(Attachment::getFilePath)
+        return ownedAttachment(attachmentId, userId);
-                .block();
-    }
-
-    public AttachmentResponse getAttachmentInfo(Long attachmentId, Long userId) {
-        return attachmentRepository.findById(attachmentId)
-                .map(this::toAttachmentResponse)
-                .block();
     }
 
     public Flux<AttachmentResponse> getMessageAttachments(Long messageId, Long userId) {
-        return attachmentRepository.findByMessageId(messageId)
+        return ownedMessage(messageId, userId)
+                .flatMapMany(message -> attachmentRepository.findByMessageId(message.getId()))
                 .map(this::toAttachmentResponse);
     }
 
     public Mono<Void> deleteAttachment(Long attachmentId, Long userId) {
-        return attachmentRepository.findById(attachmentId)
+        return ownedAttachment(attachmentId, userId)
                 .flatMap(attachment -> {
-                    try {
+                    deleteFile(attachment.getFilePath());
-                        Files.deleteIfExists(Paths.get(attachment.getFilePath()));
+                    return sources.remove(attachment.getMessageId()).then(attachmentRepository.delete(attachment));
-                    } catch (IOException e) {
-                        // Игнорируем
-                    }
-                    return attachmentRepository.delete(attachment);
                 });
     }
 
@@ -261,132 +510,6 @@ public class MailService {
         return resp;
     }
 
-    private Mono<Void> sendViaSmtp(String from, String to, String subject, String body,
-                                    boolean isHtml, String messageId) {
-        TcpClient client = TcpClient.create()
-                .host(smtpHostname)
-                .port(smtpPort)
-                .option(io.netty.channel.ChannelOption.SO_TIMEOUT, 30000)
-                .option(io.netty.channel.ChannelOption.CONNECT_TIMEOUT_MILLIS, 10000);
-
-        Properties props = new Properties();
-        Session mailSession = Session.getDefaultInstance(props);
-        MimeMessage mimeMessage = new MimeMessage(mailSession);
-        try {
-            mimeMessage.setFrom(from);
-            mimeMessage.setRecipient(jakarta.mail.Message.RecipientType.TO, new jakarta.mail.internet.InternetAddress(to));
-            mimeMessage.setSubject(subject);
-            mimeMessage.setText(body, isHtml ? "text/html" : "text/plain", "UTF-8");
-            mimeMessage.setHeader("Message-ID", "<" + messageId + "@" + smtpHostname + ">");
-            mimeMessage.setSentDate(new java.util.Date());
-
-            dkimService.signMessage(mimeMessage);
-
-            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            mimeMessage.writeTo(baos);
-            String mimeContent = baos.toString(StandardCharsets.UTF_8);
-
-            StringBuilder dataBody = new StringBuilder();
-            String[] lines = mimeContent.split("\\r?\\n");
-            for (String mimeLine : lines) {
-                if (mimeLine.startsWith(".")) {
-                    dataBody.append(".").append(mimeLine);
-                } else {
-                    dataBody.append(mimeLine);
-                }
-                dataBody.append("\r\n");
-            }
-            dataBody.append(".\r\n");
-
-            // SMTP — последовательный протокол: команда -> ответ -> команда -> ответ
-            // connection.inbound().receive() можно подписать только ОДИН раз,
-            // поэтому используем Sinks.Many с directBestEffort для шаринга ответов
-            return client.connect()
-                    .flatMap(connection -> {
-                        // Sinks.Many — один поток чтения, много подписчиков через multicast
-                        Sinks.Many<String> responseSink = Sinks.many().replay().limit(1);
-
-                        // Подписываемся на inbound ОДИН раз и пишем все ответы в sink
-                        connection.inbound()
-                                .receive()
-                                .asString(StandardCharsets.UTF_8)
-                                .doOnNext(line -> {
-                                    String trimmed = line.trim();
-                                    log.debug("SMTP клиент ответ: {}", trimmed);
-                                    responseSink.tryEmitNext(trimmed);
-                                })
-                                .subscribe();
-
-                        // Собираем все команды в список для последовательной отправки
-                        List<String> commands = new ArrayList<>();
-                        commands.add("EHLO " + smtpHostname + "\r\n");
-                        commands.add("MAIL FROM:<" + from + ">\r\n");
-                        commands.add("RCPT TO:<" + to + ">\r\n");
-                        commands.add("DATA\r\n");
-                        commands.add(dataBody.toString());
-                        commands.add("QUIT\r\n");
-
-                        // Ожидаемые коды ответов для каждой команды (включая banner)
-                        List<String> expectedCodes = new ArrayList<>();
-                        expectedCodes.add("220");  // banner
-                        expectedCodes.add("250");  // EHLO
-                        expectedCodes.add("250");  // MAIL FROM
-                        expectedCodes.add("250");  // RCPT TO
-                        expectedCodes.add("354");  // DATA
-                        expectedCodes.add("250");  // тело DATA (завершение)
-                        expectedCodes.add("221");  // QUIT
-
-                        // Последовательно отправляем команды и ждём ответы
-                        Mono<Void> send = Mono.empty();
-                        for (int i = 0; i < commands.size(); i++) {
-                            final String cmd = commands.get(i);
-                            final String expectedCode = expectedCodes.get(i);
-
-                            send = send.then(sendAndAwait(connection, cmd, responseSink, expectedCode));
-                        }
-
-                        return send.then(Mono.fromRunnable(() -> connection.dispose()));
-                    });
-
-        } catch (MessagingException | IOException e) {
-            return Mono.error(new RuntimeException("Failed to prepare SMTP message", e));
-        }
-    }
-
-    /**
-     * Отправляет SMTP команду и ждёт ответ с указанным кодом.
-     * Для многострочных ответов (EHLO) читает до строки без '-' в конце кода.
-     */
-    private Mono<Void> sendAndAwait(Connection connection, String command,
-                                     Sinks.Many<String> responseSink,
-                                     String expectedCode) {
-        log.debug("SMTP клиент команда: {}", command.trim());
-
-        // Отправляем команду
-        Mono<Void> send = connection.outbound()
-                .sendString(Mono.just(command))
-                .then();
-
-        // Ждём ответ из sink — каждый вызов получает свой Flux подписчика
-        Mono<Void> readResponse = responseSink.asFlux()
-                .takeWhile(line -> {
-                    if (expectedCode != null && line.startsWith(expectedCode + "-")) {
-                        return true;
-                    }
-                    return false;
-                })
-                .doOnNext(line -> {
-                    if (expectedCode != null && !line.startsWith(expectedCode)) {
-                        log.warn("SMTP неожиданный ответ (ожидалось {}): {}", expectedCode, line);
-                    }
-                })
-                .then()
-                .timeout(java.time.Duration.ofSeconds(30))
-                .onErrorResume(e -> Mono.error(new RuntimeException("SMTP response timeout", e)));
-
-        return send.then(readResponse);
-    }
-
     // --- Contacts ---
 
     public Flux<Contact> getContacts(Long userId) {

backend/src/main/java/com/mailserver/service/MessageSources.java

@@ -0,0 +1,38 @@
+package com.mailserver.service;
+
+import org.springframework.r2dbc.core.DatabaseClient;
+import org.springframework.stereotype.Component;
+import reactor.core.publisher.Mono;
+
+/**
+ * The message exactly as received or appended (table message_sources). IMAP serves it as BODY[]; a message without
+ * one gets its MIME text built once ({@link com.mailserver.imap.MimeSource}). A changed draft loses it.
+ */
+@Component
+public class MessageSources {
+
+    private final DatabaseClient db;
+
+    public MessageSources(DatabaseClient db) {
+        this.db = db;
+    }
+
+    public Mono<byte[]> get(Long messageId) {
+        return db.sql("SELECT raw FROM message_sources WHERE message_id = :id")
+                .bind("id", messageId)
+                .map(row -> row.get("raw", byte[].class))
+                .one();
+    }
+
+    public Mono<Void> put(Long messageId, byte[] raw) {
+        return db.sql("INSERT INTO message_sources (message_id, raw) VALUES (:id, :raw) "
+                        + "ON CONFLICT (message_id) DO UPDATE SET raw = EXCLUDED.raw")
+                .bind("id", messageId)
+                .bind("raw", raw)
+                .then();
+    }
+
+    public Mono<Void> remove(Long messageId) {
+        return db.sql("DELETE FROM message_sources WHERE message_id = :id").bind("id", messageId).then();
+    }
+}

backend/src/main/java/com/mailserver/service/SubmissionService.java

@@ -0,0 +1,168 @@
+package com.mailserver.service;
+
+import com.mailserver.domain.Attachment;
+import com.mailserver.domain.User;
+import com.mailserver.dto.MessageResponse;
+import com.mailserver.dto.SendRequest;
+import com.mailserver.repository.UserRepository;
+import com.mailserver.smtp.MailRouter;
+import com.mailserver.smtp.SmtpBackend;
+import jakarta.mail.Message;
+import jakarta.mail.MessagingException;
+import jakarta.mail.Session;
+import jakarta.mail.internet.AddressException;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeBodyPart;
+import jakarta.mail.internet.MimeMessage;
+import jakarta.mail.internet.MimeMultipart;
+import jakarta.mail.internet.MimeUtility;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.web.server.ResponseStatusException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Properties;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * "Send" in the web client: builds the MIME message (with the draft's attachments) and routes it like an
+ * authenticated SMTP submission — to every To and Cc address.
+ */
+@Service
+public class SubmissionService {
+
+    /** One message, at most this many addresses (To + Cc). */
+    static final int MAX_RECIPIENTS = 50;
+
+    private final UserRepository users;
+    private final MailService mailService;
+    private final MailRouter router;
+    private final String hostname;
+
+    public SubmissionService(UserRepository users, MailService mailService, MailRouter router,
+                             @Value("${mailserver.smtp.hostname:localhost}") String hostname) {
+        this.users = users;
+        this.mailService = mailService;
+        this.router = router;
+        this.hostname = hostname;
+    }
+
+    public Mono<MessageResponse> send(String fromEmail, SendRequest request) {
+        List<String> to = addresses(request.getTo());
+        List<String> cc = addresses(request.getCc());
+        cc.removeAll(to);
+        if (to.isEmpty()) {
+            return Mono.error(MailService.badRequest("No recipient"));
+        }
+        if (to.size() + cc.size() > MAX_RECIPIENTS) {
+            return Mono.error(MailService.badRequest("At most " + MAX_RECIPIENTS + " recipients"));
+        }
+        Long draftId = request.getDraftId();
+        return users.findByEmail(fromEmail)
+                .switchIfEmpty(Mono.error(new ResponseStatusException(HttpStatus.UNAUTHORIZED)))
+                .flatMap(user -> (draftId == null ? Flux.<Attachment>empty() : mailService.draftAttachments(draftId, user.getId()))
+                        .collectList()
+                        .flatMap(attachments -> Mono.fromCallable(() -> submit(user, to, cc, request, attachments))
+                                .subscribeOn(Schedulers.boundedElastic()))
+                        .flatMap(messageId -> mailService.saveSent(user, String.join(", ", to), String.join(", ", cc),
+                                request.getSubject(), request.getBody(), request.isHtml(), messageId))
+                        .flatMap(sent -> (draftId == null ? Mono.<Void>empty() : mailService.finishDraft(draftId, sent.getId()))
+                                .then(mailService.getMessage(sent.getId(), user.getId()))));
+    }
+
+    private String submit(User user, List<String> to, List<String> cc, SendRequest request, List<Attachment> attachments)
+            throws Exception {
+        List<SmtpBackend.Recipient> recipients = new ArrayList<>();
+        for (String address : concat(to, cc)) {
+            SmtpBackend.Route route = router.route(address, user.getEmail());
+            switch (route) {
+                case LOCAL, OUTBOUND -> recipients.add(new SmtpBackend.Recipient(address, route));
+                case UNKNOWN_USER -> throw MailService.badRequest("No such mailbox: " + address);
+                case OUTBOUND_DISABLED -> throw MailService.badRequest("Sending outside is disabled on this server: " + address);
+                case RELAY_DENIED -> throw new IllegalStateException("logged-in user denied relay");
+            }
+        }
+        String messageId = UUID.randomUUID() + "@" + hostname;
+        MimeMessage mime = mime(user, to, cc, request, attachments);
+        mime.setHeader("Message-ID", "<" + messageId + ">");
+        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+        mime.writeTo(bytes);
+        router.accept(new SmtpBackend.Envelope("127.0.0.1", hostname, user.getEmail(), user.getEmail(), recipients),
+                bytes.toByteArray());
+        return messageId;
+    }
+
+    static MimeMessage mime(User user, List<String> to, List<String> cc, SendRequest request, List<Attachment> attachments)
+            throws MessagingException, IOException {
+        MimeMessage mime = new MimeMessage(Session.getInstance(new Properties()));
+        mime.setFrom(new InternetAddress(user.getEmail(), user.getDisplayName(), "UTF-8"));
+        mime.setRecipients(Message.RecipientType.TO, InternetAddress.parse(String.join(",", to)));
+        if (!cc.isEmpty()) {
+            mime.setRecipients(Message.RecipientType.CC, InternetAddress.parse(String.join(",", cc)));
+        }
+        mime.setSubject(request.getSubject(), "UTF-8");
+        String subtype = request.isHtml() ? "html" : "plain";
+        if (attachments.isEmpty()) {
+            mime.setText(request.getBody(), "UTF-8", subtype);
+        } else {
+            MimeMultipart mixed = new MimeMultipart("mixed");
+            MimeBodyPart text = new MimeBodyPart();
+            text.setText(request.getBody(), "UTF-8", subtype);
+            mixed.addBodyPart(text);
+            for (Attachment attachment : attachments) {
+                MimeBodyPart file = new MimeBodyPart();
+                file.attachFile(new File(attachment.getFilePath()),
+                        attachment.getContentType() == null ? "application/octet-stream" : attachment.getContentType(), null);
+                file.setFileName(MimeUtility.encodeText(attachment.getFilename(), "UTF-8", null));
+                mixed.addBodyPart(file);
+            }
+            mime.setContent(mixed);
+        }
+        mime.setSentDate(new Date());
+        mime.saveChanges();
+        return mime;
+    }
+
+    /** "a@x, b@y; c@z" → lower-case addresses without repeats; a malformed one → 400. */
+    static List<String> addresses(String raw) {
+        Set<String> result = new LinkedHashSet<>();
+        if (raw == null) {
+            return new ArrayList<>();
+        }
+        for (String part : raw.split("[,;\\s]+")) {
+            String address = part.trim().toLowerCase(Locale.ROOT);
+            if (address.isEmpty()) {
+                continue;
+            }
+            try {
+                new InternetAddress(address, true).validate();
+            } catch (AddressException e) {
+                throw MailService.badRequest("Invalid address: " + address);
+            }
+            if (!address.contains("@")) {
+                throw MailService.badRequest("Invalid address: " + address);
+            }
+            result.add(address);
+        }
+        return new ArrayList<>(result);
+    }
+
+    private static List<String> concat(List<String> a, List<String> b) {
+        List<String> all = new ArrayList<>(a);
+        all.addAll(b);
+        return all;
+    }
+
+}

backend/src/main/java/com/mailserver/service/UserService.java

@@ -2,7 +2,6 @@ package com.mailserver.service;
 
 import com.mailserver.domain.Folder;
 import com.mailserver.domain.User;
-import com.mailserver.dto.FolderResponse;
 import com.mailserver.repository.FolderRepository;
 import com.mailserver.repository.UserRepository;
 import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
@@ -35,18 +34,18 @@ public class UserService {
                     User user = new User();
                     user.setEmail(email);
                     user.setPassword(passwordEncoder.encode(password));
-                    user.setDisplayName(displayName);
+                    user.setDisplayName(displayName == null || displayName.isBlank() ? email.substring(0, email.indexOf('@')) : displayName.trim());
                     user.setCreatedAt(Instant.now());
                     return userRepository.save(user);
                 })
                 .flatMap(user -> {
                     // Создаём стандартные папки
-                    String[] defaultFolders = {"INBOX", "Sent", "Drafts", "Trash", "Spam"};
+                    return Flux.fromIterable(MailService.SYSTEM_FOLDERS)
-                    return Flux.fromArray(defaultFolders)
+                            .concatMap(name -> {
-                            .flatMap(name -> {
                                 Folder folder = new Folder();
                                 folder.setUserId(user.getId());
                                 folder.setName(name);
+                                folder.setSystem(true);
                                 folder.setCreatedAt(Instant.now());
                                 return folderRepository.save(folder);
                             })
@@ -66,15 +65,36 @@ public class UserService {
         return passwordEncoder.matches(rawPassword, user.getPassword());
     }
 
-    public Flux<FolderResponse> getFolders(Long userId) {
+    /** New password, only with the current one. */
-        return folderRepository.findByUserId(userId)
+    public Mono<Void> changePassword(User user, String currentPassword, String newPassword) {
-                .map(f -> {
+        if (!checkPassword(user, currentPassword)) {
-                    FolderResponse resp = new FolderResponse();
+            return Mono.error(MailService.badRequest("Current password is wrong"));
-                    resp.setId(f.getId());
+        }
-                    resp.setName(f.getName());
+        user.setPassword(passwordEncoder.encode(newPassword));
-                    resp.setMessageCount(f.getMessageCount());
+        return userRepository.save(user).then();
-                    resp.setUnreadCount(f.getUnreadCount());
+    }
-                    return resp;
+
-                });
+    public Flux<User> all() {
+        return userRepository.findAll();
+    }
+
+    public Mono<User> byId(Long id) {
+        return userRepository.findById(id);
+    }
+
+    /** Administrator sets a new password (Settings → Mailboxes): no current password needed. */
+    public Mono<User> setPassword(User user, String newPassword) {
+        user.setPassword(passwordEncoder.encode(newPassword));
+        return userRepository.save(user);
+    }
+
+    public Mono<User> setActive(User user, boolean active) {
+        user.setActive(active);
+        return userRepository.save(user);
+    }
+
+    public Mono<User> updateDisplayName(User user, String displayName) {
+        user.setDisplayName(displayName.trim());
+        return userRepository.save(user);
     }
 }

backend/src/main/java/com/mailserver/smtp/MailRouter.java

@@ -0,0 +1,98 @@
+package com.mailserver.smtp;
+
+import com.mailserver.config.MailDomains;
+import com.mailserver.delivery.OutboundQueue;
+import com.mailserver.delivery.SmtpDeliveryClient;
+import com.mailserver.domain.User;
+import com.mailserver.repository.UserRepository;
+import com.mailserver.service.DkimService;
+import com.mailserver.service.LocalDelivery;
+import com.mailserver.service.UserService;
+import org.springframework.stereotype.Service;
+
+import java.util.Locale;
+
+/**
+ * Where mail goes — one rule for SMTP and for the web client:
+ * an existing mailbox of our domain → that mailbox; catch-all set → everything else into the catch-all mailbox
+ * (nothing goes outside, existing mailboxes still get their own mail); otherwise our domain without such a mailbox →
+ * "no such user", someone else's domain → the delivery queue, only for a logged-in sender (never an open relay).
+ */
+@Service
+public class MailRouter implements SmtpBackend {
+
+    private final MailDomains domains;
+    private final UserRepository users;
+    private final UserService userService;
+    private final LocalDelivery localDelivery;
+    private final OutboundQueue queue;
+    private final DkimService dkim;
+    private final SmtpDeliveryClient client;
+
+    public MailRouter(MailDomains domains, UserRepository users, UserService userService, LocalDelivery localDelivery,
+                      OutboundQueue queue, DkimService dkim, SmtpDeliveryClient client) {
+        this.domains = domains;
+        this.users = users;
+        this.userService = userService;
+        this.localDelivery = localDelivery;
+        this.queue = queue;
+        this.dkim = dkim;
+        this.client = client;
+    }
+
+    @Override
+    public boolean authenticate(String username, String password) {
+        User user = users.findByEmail(username.toLowerCase(Locale.ROOT)).block();
+        return user != null && user.isActive() && userService.checkPassword(user, password);
+    }
+
+    @Override
+    public Route route(String recipient, String authenticatedUser) {
+        if (domains.isLocal(recipient) && mailboxExists(recipient)) {
+            return Route.LOCAL;
+        }
+        if (domains.catchAll() != null) {
+            return Route.LOCAL;
+        }
+        if (domains.isLocal(recipient)) {
+            return Route.UNKNOWN_USER;
+        }
+        if (authenticatedUser == null) {
+            return Route.RELAY_DENIED;
+        }
+        return client.mode() == SmtpDeliveryClient.Mode.OFF ? Route.OUTBOUND_DISABLED : Route.OUTBOUND;
+    }
+
+    @Override
+    public void accept(Envelope envelope, byte[] message) throws Exception {
+        boolean trusted = envelope.authenticatedUser() != null;
+        byte[] signed = null;
+        for (Recipient recipient : envelope.recipients()) {
+            switch (recipient.route()) {
+                case LOCAL -> {
+                    String mailbox = mailbox(recipient.address());
+                    localDelivery.deliver(message, mailbox, envelope.remoteIp(), envelope.mailFrom(), trusted);
+                }
+                case OUTBOUND -> {
+                    if (signed == null) {
+                        signed = dkim.sign(message);
+                    }
+                    queue.enqueue(envelope.mailFrom(), recipient.address(), signed).block();
+                }
+                default -> throw new IllegalStateException("Recipient was not accepted: " + recipient);
+            }
+        }
+    }
+
+    /** Mailbox that stores mail to this address: its own if it exists here, otherwise the catch-all one. */
+    String mailbox(String address) {
+        if (domains.catchAll() == null || (domains.isLocal(address) && mailboxExists(address))) {
+            return address;
+        }
+        return domains.catchAll();
+    }
+
+    private boolean mailboxExists(String address) {
+        return Boolean.TRUE.equals(users.existsByEmail(address.toLowerCase(Locale.ROOT)).block());
+    }
+}

backend/src/main/java/com/mailserver/smtp/ReloadingKeyManager.java

@@ -0,0 +1,194 @@
+package com.mailserver.smtp;
+
+import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
+import org.bouncycastle.openssl.PEMKeyPair;
+import org.bouncycastle.openssl.PEMParser;
+import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.net.ssl.SSLEngine;
+import javax.net.ssl.X509ExtendedKeyManager;
+import java.io.InputStream;
+import java.io.Reader;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.FileTime;
+import java.security.Principal;
+import java.security.PrivateKey;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+import java.time.Clock;
+import java.time.Duration;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Server certificate and key from PEM files, read again when the files change — a Let's Encrypt certificate
+ * renewed on disk (lego, certbot) is picked up without a restart, for STARTTLS and implicit TLS alike: the JDK
+ * asks the key manager on every handshake. The files are checked at most once per {@code interval}; a file
+ * that cannot be read (a renewal half written) keeps the previous certificate and is tried again next time.
+ * <p>
+ * Key: PKCS#8 ({@code PRIVATE KEY}) or the traditional {@code RSA PRIVATE KEY} / {@code EC PRIVATE KEY} that
+ * lego and certbot write. Each loaded pair gets its own alias, so a handshake that asks for the chain and then
+ * for the key never mixes two generations.
+ */
+public final class ReloadingKeyManager extends X509ExtendedKeyManager {
+
+    private static final Logger log = LoggerFactory.getLogger(ReloadingKeyManager.class);
+    private static final String ALIAS_PREFIX = "mail-";
+
+    record Material(String alias, X509Certificate[] chain, PrivateKey key, FileTime certTime, FileTime keyTime) {
+    }
+
+    private final Path certFile;
+    private final Path keyFile;
+    private final Duration interval;
+    private final Clock clock;
+    /** The current pair and the one before it (a handshake may still hold its alias) */
+    private final Map<String, Material> byAlias = new ConcurrentHashMap<>();
+    private volatile Material current;
+    private volatile long checkedAt;
+    private int generation;
+
+    public ReloadingKeyManager(Path certFile, Path keyFile, Duration interval, Clock clock) throws Exception {
+        this.certFile = certFile;
+        this.keyFile = keyFile;
+        this.interval = interval;
+        this.clock = clock;
+        install(load());
+        this.checkedAt = clock.millis();
+    }
+
+    /** The pair to use now; reads the files again when the interval has passed and they changed */
+    Material material() {
+        long now = clock.millis();
+        if (now - checkedAt >= interval.toMillis()) {
+            synchronized (this) {
+                if (now - checkedAt >= interval.toMillis()) {
+                    checkedAt = now;
+                    reloadIfChanged();
+                }
+            }
+        }
+        return current;
+    }
+
+    private void reloadIfChanged() {
+        Material old = current;
+        try {
+            if (Files.getLastModifiedTime(certFile).equals(old.certTime())
+                    && Files.getLastModifiedTime(keyFile).equals(old.keyTime())) {
+                return;
+            }
+            Material fresh = load();
+            install(fresh);
+            log.info("TLS: certificate {} reloaded, valid until {}", certFile, fresh.chain()[0].getNotAfter());
+        } catch (Exception e) {
+            log.warn("TLS: cannot read {} / {} ({}), keeping the certificate valid until {}",
+                    certFile, keyFile, e.toString(), old.chain()[0].getNotAfter());
+        }
+    }
+
+    private synchronized void install(Material material) {
+        Material previous = current;
+        byAlias.keySet().removeIf(alias -> previous == null || !alias.equals(previous.alias()));
+        byAlias.put(material.alias(), material);
+        current = material;
+    }
+
+    private Material load() throws Exception {
+        FileTime certTime = Files.getLastModifiedTime(certFile);
+        FileTime keyTime = Files.getLastModifiedTime(keyFile);
+        X509Certificate[] chain;
+        try (InputStream in = Files.newInputStream(certFile)) {
+            chain = CertificateFactory.getInstance("X.509").generateCertificates(in).stream()
+                    .map(X509Certificate.class::cast).toArray(X509Certificate[]::new);
+        }
+        if (chain.length == 0) {
+            throw new IllegalStateException("no certificate in " + certFile);
+        }
+        PrivateKey key = readKey(keyFile);
+        if (!chain[0].getPublicKey().getAlgorithm().equals(key.getAlgorithm())) {
+            throw new IllegalStateException("the key in " + keyFile + " is " + key.getAlgorithm()
+                    + ", the certificate is " + chain[0].getPublicKey().getAlgorithm());
+        }
+        String alias;
+        synchronized (this) {
+            alias = ALIAS_PREFIX + (++generation);
+        }
+        return new Material(alias, chain, key, certTime, keyTime);
+    }
+
+    static PrivateKey readKey(Path file) throws Exception {
+        try (Reader reader = Files.newBufferedReader(file, StandardCharsets.US_ASCII);
+             PEMParser parser = new PEMParser(reader)) {
+            Object object;
+            while ((object = parser.readObject()) != null) {
+                JcaPEMKeyConverter converter = new JcaPEMKeyConverter();
+                if (object instanceof PrivateKeyInfo info) {
+                    return converter.getPrivateKey(info);
+                }
+                if (object instanceof PEMKeyPair pair) {
+                    return converter.getPrivateKey(pair.getPrivateKeyInfo()); // SEC1 may come without the public part
+                }
+                // EC PARAMETERS before EC PRIVATE KEY (openssl ecparam -genkey) — skip
+            }
+        }
+        throw new IllegalStateException("no private key in " + file);
+    }
+
+    private String serverAlias(String keyType) {
+        Material material = material();
+        String algorithm = material.key().getAlgorithm();
+        boolean fits = keyType == null || keyType.equalsIgnoreCase(algorithm)
+                || ("RSA".equals(algorithm) && keyType.equalsIgnoreCase("RSASSA-PSS"))
+                || ("EC".equals(algorithm) && keyType.toUpperCase().startsWith("EC"));
+        return fits ? material.alias() : null;
+    }
+
+    @Override
+    public String chooseServerAlias(String keyType, Principal[] issuers, Socket socket) {
+        return serverAlias(keyType);
+    }
+
+    @Override
+    public String chooseEngineServerAlias(String keyType, Principal[] issuers, SSLEngine engine) {
+        return serverAlias(keyType);
+    }
+
+    @Override
+    public String[] getServerAliases(String keyType, Principal[] issuers) {
+        String alias = serverAlias(keyType);
+        return alias == null ? null : new String[]{alias};
+    }
+
+    @Override
+    public X509Certificate[] getCertificateChain(String alias) {
+        Material material = alias == null ? null : byAlias.get(alias);
+        return material == null ? null : material.chain().clone();
+    }
+
+    @Override
+    public PrivateKey getPrivateKey(String alias) {
+        Material material = alias == null ? null : byAlias.get(alias);
+        return material == null ? null : material.key();
+    }
+
+    @Override
+    public String[] getClientAliases(String keyType, Principal[] issuers) {
+        return null;
+    }
+
+    @Override
+    public String chooseClientAlias(String[] keyType, Principal[] issuers, Socket socket) {
+        return null;
+    }
+
+    @Override
+    public String chooseEngineClientAlias(String[] keyType, Principal[] issuers, SSLEngine engine) {
+        return null;
+    }
+}

backend/src/main/java/com/mailserver/smtp/SmtpBackend.java

@@ -0,0 +1,41 @@
+package com.mailserver.smtp;
+
+import java.util.List;
+
+/**
+ * What the SMTP server asks the rest of the application. All methods may block (database, DNS):
+ * the server calls them on a worker thread, never on the network event loop.
+ */
+public interface SmtpBackend {
+
+    /** Where a recipient goes, decided at RCPT TO. */
+    enum Route {
+        /** A mailbox of ours (or the catch-all mailbox) — store it. */
+        LOCAL,
+        /** Someone else's address, sender is logged in — queue for delivery. */
+        OUTBOUND,
+        /** Address of our domain that does not exist. */
+        UNKNOWN_USER,
+        /** Someone else's address and the sender is not logged in: we are not an open relay. */
+        RELAY_DENIED,
+        /** Someone else's address, outbound delivery is switched off on this server. */
+        OUTBOUND_DISABLED
+    }
+
+    record Recipient(String address, Route route) {
+    }
+
+    record Envelope(String remoteIp, String helo, String mailFrom, String authenticatedUser, List<Recipient> recipients) {
+    }
+
+    /** true — the address and password belong to an active mailbox. */
+    boolean authenticate(String username, String password);
+
+    Route route(String recipient, String authenticatedUser);
+
+    /**
+     * Stores or queues the message for every recipient. Returns normally only when the message is safe
+     * (stored or queued) — then the client gets 250. Any exception → 451, the client will retry.
+     */
+    void accept(Envelope envelope, byte[] message) throws Exception;
+}

backend/src/main/java/com/mailserver/smtp/SmtpServer.java

@@ -0,0 +1,591 @@
+package com.mailserver.smtp;
+
+import com.mailserver.security.LoginGuard;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import io.netty.handler.codec.MessageToMessageDecoder;
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.SslHandler;
+import io.netty.handler.timeout.ReadTimeoutHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+import reactor.netty.Connection;
+import reactor.netty.DisposableServer;
+import reactor.netty.NettyOutbound;
+import reactor.netty.tcp.TcpServer;
+
+import java.io.ByteArrayOutputStream;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.List;
+import java.util.Locale;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * SMTP server (RFC 5321) on Reactor Netty.
+ * <ul>
+ *   <li>input is split into lines by {@link LineBasedFrameDecoder} — a network packet may hold half a line or many
+ *       pipelined commands, both work;</li>
+ *   <li>AUTH PLAIN / LOGIN against our mailboxes; someone else's address is accepted only from a logged-in sender
+ *       (no open relay); a logged-in sender may use only his own address in MAIL FROM;</li>
+ *   <li>the message is stored or queued before the client gets 250 — on failure 451 and the client retries;</li>
+ *   <li>database and DNS work runs on a worker thread, not on the event loop.</li>
+ * </ul>
+ * TLS (RFC 3207 STARTTLS, or implicit TLS on a separate port, RFC 8314): with a {@code tls} context STARTTLS is
+ * offered; AUTH only over TLS, or without it when {@code authWithoutTls} is on (a closed network: VM, docker network).
+ * After STARTTLS the session starts over (new EHLO), and lines sent in plain text together with STARTTLS are not
+ * executed — the connection is closed (command injection, CVE-2011-0411).
+ */
+public class SmtpServer {
+
+    private static final Logger log = LoggerFactory.getLogger(SmtpServer.class);
+
+    // RFC 5321 4.5.3.1.6: a text line is at most 1000 octets with CRLF; we allow more for sloppy clients
+    static final int MAX_LINE = 64 * 1024;
+    static final int MAX_RECIPIENTS = 100;
+    private static final int MAX_BAD_COMMANDS = 20;
+    /** Wrong passwords in one connection before it is closed. */
+    private static final int MAX_AUTH_FAILURES = 3;
+    // Compared by identity: TLS starts right after exactly this reply is written
+    private static final String STARTTLS_READY = new String("220 2.0.0 Ready to start TLS\r\n");
+
+    /**
+     * @param tls         certificate for STARTTLS / implicit TLS; null — no TLS
+     * @param implicitTls TLS from the first byte (port 465), no STARTTLS
+     */
+    public record Settings(String host, int port, String hostname, long maxMessageBytes, boolean authWithoutTls,
+                           Duration idleTimeout, SslContext tls, boolean implicitTls) {
+
+        public Settings(String host, int port, String hostname, long maxMessageBytes, boolean authWithoutTls,
+                        Duration idleTimeout) {
+            this(host, port, hostname, maxMessageBytes, authWithoutTls, idleTimeout, null, false);
+        }
+    }
+
+    /** A line of input and whether it came over TLS. */
+    record Line(byte[] bytes, boolean tls) {
+    }
+
+    /** Marks each line: decoded behind an SslHandler (encrypted) or not. */
+    private static final class LineTagger extends MessageToMessageDecoder<ByteBuf> {
+        @Override
+        protected void decode(ChannelHandlerContext ctx, ByteBuf frame, List<Object> out) {
+            out.add(new Line(ByteBufUtil.getBytes(frame), ctx.pipeline().get(SslHandler.class) != null));
+        }
+    }
+
+    private final Settings settings;
+    private final SmtpBackend backend;
+    private final LoginGuard guard;
+    private DisposableServer server;
+
+    public SmtpServer(Settings settings, SmtpBackend backend) {
+        this(settings, backend, LoginGuard.disabled());
+    }
+
+    public SmtpServer(Settings settings, SmtpBackend backend, LoginGuard guard) {
+        this.settings = settings;
+        this.backend = backend;
+        this.guard = guard;
+    }
+
+    public void start() {
+        if (settings.implicitTls() && settings.tls() == null) {
+            throw new IllegalStateException("Implicit TLS needs a certificate");
+        }
+        TcpServer tcp = TcpServer.create()
+                .host(settings.host())
+                .port(settings.port())
+                .doOnConnection(connection -> connection
+                        .addHandlerFirst("smtp-idle", new ReadTimeoutHandler(settings.idleTimeout().toSeconds(), TimeUnit.SECONDS))
+                        .addHandlerLast("smtp-lines", new LineBasedFrameDecoder(MAX_LINE, true, false))
+                        .addHandlerLast("smtp-tag", new LineTagger()));
+        if (settings.implicitTls()) {
+            tcp = tcp.secure(spec -> spec.sslContext(settings.tls()));
+        }
+        server = tcp
+                .handle((inbound, outbound) -> {
+                    Connection[] connection = {null};
+                    String[] remoteIp = {"unknown"};
+                    inbound.withConnection(c -> {
+                        connection[0] = c;
+                        if (c.address() instanceof InetSocketAddress address && address.getAddress() != null) {
+                            remoteIp[0] = address.getAddress().getHostAddress();
+                        }
+                    });
+                    Session session = new Session(remoteIp[0], settings.implicitTls());
+                    Flux<String> replies = inbound.receiveObject().cast(Line.class)
+                            .concatMap(session::onLine)
+                            .onErrorResume(e -> {
+                                log.debug("SMTP {}: connection closed: {}", session.remoteIp, e.toString());
+                                return Mono.just("421 4.4.2 " + settings.hostname() + " closing connection\r\n");
+                            })
+                            .takeUntil(reply -> session.closing);
+                    // One reply at a time, each written before the next line is handled: after "220 Ready to start TLS"
+                    // the TLS handler goes in only when the reply has left in plain text
+                    return Flux.concat(Mono.just("220 " + settings.hostname() + " ESMTP ready\r\n"), replies)
+                            .concatMap(reply -> send(outbound, reply)
+                                    .then(Mono.defer(() -> reply == STARTTLS_READY ? startTls(connection[0], session) : Mono.<Void>empty())))
+                            .then();
+                })
+                .bindNow(Duration.ofSeconds(10));
+        log.info("SMTP server listening on {}:{} ({}{})", settings.host(), port(), settings.hostname(),
+                settings.implicitTls() ? ", implicit TLS" : settings.tls() != null ? ", STARTTLS" : ", no TLS");
+    }
+
+    private static Mono<Void> send(NettyOutbound outbound, String reply) {
+        return outbound.sendString(Mono.just(reply), StandardCharsets.US_ASCII).then();
+    }
+
+    /** TLS handler in front, fresh line decoder (no plain-text leftovers mixed into encrypted input). */
+    private Mono<Void> startTls(Connection connection, Session session) {
+        ChannelPipeline pipeline = connection.channel().pipeline();
+        SslHandler ssl = settings.tls().newHandler(connection.channel().alloc());
+        pipeline.replace("smtp-lines", "smtp-lines", new LineBasedFrameDecoder(MAX_LINE, true, false));
+        pipeline.addFirst("smtp-tls", ssl);
+        return Mono.create(sink -> ssl.handshakeFuture().addListener(future -> {
+            if (future.isSuccess()) {
+                log.debug("SMTP {}: TLS {}", session.remoteIp, ssl.engine().getSession().getProtocol());
+                sink.success();
+            } else {
+                log.info("SMTP {}: TLS handshake failed: {}", session.remoteIp, future.cause().toString());
+                session.closing = true;
+                connection.dispose();
+                sink.success();
+            }
+        }));
+    }
+
+    public int port() {
+        return server.port();
+    }
+
+    public void stop() {
+        if (server != null) {
+            server.disposeNow(Duration.ofSeconds(5));
+        }
+    }
+
+    private enum State { COMMAND, DATA, AUTH_PLAIN, AUTH_LOGIN_USER, AUTH_LOGIN_PASSWORD }
+
+    private final class Session {
+        final String remoteIp;
+        boolean tls;
+        State state = State.COMMAND;
+        String helo;
+        boolean extended;
+        String authenticatedUser;
+        String pendingAuthUser;
+        String mailFrom;
+        final List<SmtpBackend.Recipient> recipients = new ArrayList<>();
+        final ByteArrayOutputStream data = new ByteArrayOutputStream();
+        boolean dataTooBig;
+        int badCommands;
+        int authFailures;
+        volatile boolean closing;
+
+        Session(String remoteIp, boolean tls) {
+            this.remoteIp = remoteIp;
+            this.tls = tls;
+        }
+
+        Mono<String> onLine(Line input) {
+            if (tls && !input.tls()) {
+                // Sent in plain text after STARTTLS, before the handshake: never execute it
+                return Mono.error(new IllegalStateException("plain-text input after STARTTLS"));
+            }
+            byte[] line = stripCr(input.bytes());
+            return switch (state) {
+                case DATA -> onDataLine(line);
+                case AUTH_PLAIN -> authPlain(ascii(line));
+                case AUTH_LOGIN_USER -> authLoginUser(ascii(line));
+                case AUTH_LOGIN_PASSWORD -> authLoginPassword(ascii(line));
+                case COMMAND -> onCommand(ascii(line));
+            };
+        }
+
+        private Mono<String> onCommand(String line) {
+            String[] parts = line.trim().split("\\s+", 2);
+            String verb = parts[0].toUpperCase(Locale.ROOT);
+            String arg = parts.length > 1 ? parts[1].trim() : "";
+            return switch (verb) {
+                case "EHLO", "HELO" -> hello(verb.equals("EHLO"), arg);
+                case "AUTH" -> auth(arg);
+                case "MAIL" -> mail(arg);
+                case "RCPT" -> rcpt(arg);
+                case "DATA" -> dataStart();
+                case "RSET" -> {
+                    resetTransaction();
+                    yield reply("250 2.0.0 OK");
+                }
+                case "NOOP" -> reply("250 2.0.0 OK");
+                case "VRFY" -> reply("252 2.5.0 Cannot VRFY user, but will accept message");
+                case "STARTTLS" -> startTls(arg);
+                case "QUIT" -> {
+                    closing = true;
+                    yield reply("221 2.0.0 " + settings.hostname() + " Bye");
+                }
+                case "" -> reply("500 5.5.2 Empty command");
+                default -> bad("500 5.5.1 Command not recognized");
+            };
+        }
+
+        private Mono<String> hello(boolean ehlo, String arg) {
+            if (arg.isEmpty()) {
+                return reply("501 5.5.4 Hostname required");
+            }
+            helo = arg;
+            extended = ehlo;
+            resetTransaction();
+            if (!ehlo) {
+                return reply("250 " + settings.hostname());
+            }
+            StringBuilder sb = new StringBuilder();
+            sb.append("250-").append(settings.hostname()).append(" Hello ").append(arg).append("\r\n");
+            sb.append("250-SIZE ").append(settings.maxMessageBytes()).append("\r\n");
+            sb.append("250-8BITMIME\r\n");
+            sb.append("250-PIPELINING\r\n");
+            if (settings.tls() != null && !tls) {
+                sb.append("250-STARTTLS\r\n");
+            }
+            if (authAllowed()) {
+                sb.append("250-AUTH PLAIN LOGIN\r\n");
+            }
+            sb.append("250 ENHANCEDSTATUSCODES\r\n");
+            return Mono.just(sb.toString());
+        }
+
+        private boolean authAllowed() {
+            return tls || settings.authWithoutTls();
+        }
+
+        private Mono<String> startTls(String arg) {
+            if (settings.tls() == null) {
+                return reply("454 4.7.0 TLS not available");
+            }
+            if (tls) {
+                return bad("503 5.5.1 TLS already active");
+            }
+            if (!arg.isEmpty()) {
+                return reply("501 5.5.4 Syntax: STARTTLS");
+            }
+            // RFC 3207 4.2: everything known about the client is forgotten, a new EHLO is expected
+            tls = true;
+            helo = null;
+            extended = false;
+            authenticatedUser = null;
+            resetTransaction();
+            return Mono.just(STARTTLS_READY);
+        }
+
+        private Mono<String> auth(String arg) {
+            if (!authAllowed()) {
+                return reply("538 5.7.11 Encryption required for requested authentication mechanism");
+            }
+            if (helo == null || !extended) {
+                return reply("503 5.5.1 EHLO first");
+            }
+            if (authenticatedUser != null) {
+                return reply("503 5.5.1 Already authenticated");
+            }
+            if (mailFrom != null) {
+                return reply("503 5.5.1 AUTH not allowed during a mail transaction");
+            }
+            String[] parts = arg.split("\\s+", 2);
+            String mechanism = parts[0].toUpperCase(Locale.ROOT);
+            String initial = parts.length > 1 ? parts[1] : null;
+            if (mechanism.equals("PLAIN")) {
+                if (initial == null) {
+                    state = State.AUTH_PLAIN;
+                    return reply("334 ");
+                }
+                return authPlain(initial);
+            }
+            if (mechanism.equals("LOGIN")) {
+                if (initial != null) {
+                    return authLoginUser(initial);
+                }
+                state = State.AUTH_LOGIN_USER;
+                return reply("334 " + b64("Username:"));
+            }
+            return reply("504 5.5.4 Unrecognized authentication type");
+        }
+
+        private Mono<String> authPlain(String response) {
+            state = State.COMMAND;
+            if (response.equals("*")) {
+                return reply("501 5.0.0 Authentication cancelled");
+            }
+            String decoded = unb64(response);
+            // authzid \0 authcid \0 password
+            String[] fields = decoded == null ? new String[0] : decoded.split("\0", -1);
+            if (fields.length != 3) {
+                return reply("501 5.5.2 Cannot decode AUTH PLAIN response");
+            }
+            return checkPassword(fields[1], fields[2]);
+        }
+
+        private Mono<String> authLoginUser(String response) {
+            if (response.equals("*")) {
+                state = State.COMMAND;
+                return reply("501 5.0.0 Authentication cancelled");
+            }
+            pendingAuthUser = unb64(response);
+            if (pendingAuthUser == null) {
+                state = State.COMMAND;
+                return reply("501 5.5.2 Cannot decode username");
+            }
+            state = State.AUTH_LOGIN_PASSWORD;
+            return reply("334 " + b64("Password:"));
+        }
+
+        private Mono<String> authLoginPassword(String response) {
+            state = State.COMMAND;
+            String user = pendingAuthUser;
+            pendingAuthUser = null;
+            if (response.equals("*")) {
+                return reply("501 5.0.0 Authentication cancelled");
+            }
+            String password = unb64(response);
+            if (password == null) {
+                return reply("501 5.5.2 Cannot decode password");
+            }
+            return checkPassword(user, password);
+        }
+
+        private Mono<String> checkPassword(String user, String password) {
+            String username = user.trim().toLowerCase(Locale.ROOT);
+            Duration wait = guard.retryAfter(remoteIp, username);
+            if (!wait.isZero()) {
+                // Blocked: the password is not even checked, the connection is closed
+                log.warn("SMTP {}: login as {} refused, blocked for {}", remoteIp, username, LoginGuard.human(wait));
+                closing = true;
+                return reply("421 4.7.0 Too many failed logins, try again in " + LoginGuard.human(wait));
+            }
+            return blocking(() -> backend.authenticate(username, password))
+                    .flatMap(ok -> {
+                        if (ok) {
+                            guard.success(remoteIp, username);
+                            authenticatedUser = username;
+                            log.info("SMTP {}: authenticated as {}", remoteIp, username);
+                            return Mono.just("235 2.7.0 Authentication successful\r\n");
+                        }
+                        guard.failure(remoteIp, username);
+                        log.warn("SMTP {}: authentication failed for {}", remoteIp, username);
+                        badCommands++;
+                        if (++authFailures >= MAX_AUTH_FAILURES) {
+                            closing = true;
+                        }
+                        String answer = closing
+                                ? "535 5.7.8 Authentication credentials invalid, closing connection\r\n"
+                                : "535 5.7.8 Authentication credentials invalid\r\n";
+                        Duration delay = guard.failureDelay();
+                        return delay.isZero() ? Mono.just(answer) : Mono.just(answer).delayElement(delay);
+                    });
+        }
+
+        private Mono<String> mail(String arg) {
+            if (helo == null) {
+                return reply("503 5.5.1 EHLO/HELO first");
+            }
+            if (mailFrom != null) {
+                return reply("503 5.5.1 Sender already specified");
+            }
+            if (!arg.regionMatches(true, 0, "FROM:", 0, 5)) {
+                return reply("501 5.5.4 Syntax: MAIL FROM:<address>");
+            }
+            String rest = arg.substring(5).trim();
+            String address = path(rest);
+            if (address == null) {
+                return reply("501 5.1.7 Bad sender address syntax");
+            }
+            Long size = sizeParam(rest);
+            if (size != null && size > settings.maxMessageBytes()) {
+                return reply("552 5.3.4 Message size exceeds fixed limit");
+            }
+            if (authenticatedUser != null && !address.isEmpty() && !address.equals(authenticatedUser)) {
+                return reply("553 5.7.1 Sender address not owned by authenticated user");
+            }
+            mailFrom = address;
+            return reply("250 2.1.0 Sender OK");
+        }
+
+        private Mono<String> rcpt(String arg) {
+            if (mailFrom == null) {
+                return reply("503 5.5.1 MAIL first");
+            }
+            if (!arg.regionMatches(true, 0, "TO:", 0, 3)) {
+                return reply("501 5.5.4 Syntax: RCPT TO:<address>");
+            }
+            String address = path(arg.substring(3).trim());
+            if (address == null || address.isEmpty() || address.indexOf('@') < 1) {
+                return reply("501 5.1.3 Bad recipient address syntax");
+            }
+            if (recipients.size() >= MAX_RECIPIENTS) {
+                return reply("452 4.5.3 Too many recipients");
+            }
+            String user = authenticatedUser;
+            return blocking(() -> backend.route(address, user))
+                    .map(route -> switch (route) {
+                        case LOCAL, OUTBOUND -> {
+                            recipients.add(new SmtpBackend.Recipient(address, route));
+                            yield "250 2.1.5 Recipient OK\r\n";
+                        }
+                        case UNKNOWN_USER -> "550 5.1.1 No such user here\r\n";
+                        case RELAY_DENIED -> {
+                            log.warn("SMTP {}: relay denied {} -> {}", remoteIp, mailFrom, address);
+                            yield "550 5.7.1 Relaying denied: authentication required\r\n";
+                        }
+                        case OUTBOUND_DISABLED -> "550 5.7.1 Outbound delivery is disabled on this server\r\n";
+                    });
+        }
+
+        private Mono<String> dataStart() {
+            if (mailFrom == null) {
+                return reply("503 5.5.1 MAIL first");
+            }
+            if (recipients.isEmpty()) {
+                return reply("554 5.5.1 No valid recipients");
+            }
+            state = State.DATA;
+            data.reset();
+            dataTooBig = false;
+            return reply("354 End data with <CR><LF>.<CR><LF>");
+        }
+
+        private Mono<String> onDataLine(byte[] line) {
+            if (line.length == 1 && line[0] == '.') {
+                state = State.COMMAND;
+                if (dataTooBig) {
+                    resetTransaction();
+                    return reply("552 5.3.4 Message size exceeds fixed limit");
+                }
+                SmtpBackend.Envelope envelope = new SmtpBackend.Envelope(
+                        remoteIp, helo, mailFrom, authenticatedUser, List.copyOf(recipients));
+                byte[] message = withReceivedHeader(data.toByteArray());
+                resetTransaction();
+                return blocking(() -> {
+                    backend.accept(envelope, message);
+                    return true;
+                })
+                        .map(ok -> "250 2.0.0 Message accepted\r\n")
+                        .onErrorResume(e -> {
+                            log.error("SMTP {}: message from {} not stored: {}", remoteIp, envelope.mailFrom(), e.toString());
+                            return Mono.just("451 4.3.0 Message not stored, try again later\r\n");
+                        });
+            }
+            if (!dataTooBig) {
+                int offset = line.length > 0 && line[0] == '.' ? 1 : 0; // dot-unstuffing (RFC 5321 4.5.2)
+                data.write(line, offset, line.length - offset);
+                data.write('\r');
+                data.write('\n');
+                if (data.size() > settings.maxMessageBytes()) {
+                    dataTooBig = true;
+                    data.reset();
+                }
+            }
+            return Mono.empty();
+        }
+
+        private byte[] withReceivedHeader(byte[] message) {
+            String received = "Received: from " + helo + " ([" + remoteIp + "])\r\n"
+                    + "\tby " + settings.hostname() + " with " + (tls ? "ESMTPS" : "ESMTP") + (authenticatedUser != null ? "A" : "") + ";\r\n"
+                    + "\t" + DateTimeFormatter.RFC_1123_DATE_TIME.format(ZonedDateTime.now()) + "\r\n";
+            byte[] header = received.getBytes(StandardCharsets.US_ASCII);
+            byte[] all = new byte[header.length + message.length];
+            System.arraycopy(header, 0, all, 0, header.length);
+            System.arraycopy(message, 0, all, header.length, message.length);
+            return all;
+        }
+
+        private void resetTransaction() {
+            mailFrom = null;
+            recipients.clear();
+            data.reset();
+            dataTooBig = false;
+        }
+
+        private Mono<String> bad(String text) {
+            if (++badCommands > MAX_BAD_COMMANDS) {
+                closing = true;
+                return reply("421 4.7.0 Too many errors, closing connection");
+            }
+            return reply(text);
+        }
+    }
+
+    private static Mono<String> reply(String line) {
+        return Mono.just(line + "\r\n");
+    }
+
+    private static <T> Mono<T> blocking(java.util.concurrent.Callable<T> work) {
+        return Mono.fromCallable(work).subscribeOn(Schedulers.boundedElastic());
+    }
+
+    /** "<a@b> SIZE=1" → "a@b"; "<>" → "" (null sender of bounces); malformed → null. */
+    static String path(String text) {
+        int start = text.indexOf('<');
+        int end = text.indexOf('>', start + 1);
+        if (start != 0 || end < 0) {
+            return null;
+        }
+        String address = text.substring(1, end).trim();
+        int colon = address.indexOf(':'); // source route "@a,@b:user@host" (RFC 5321 4.1.2) — ignored
+        if (address.startsWith("@") && colon > 0) {
+            address = address.substring(colon + 1);
+        }
+        if (address.contains(" ") || address.contains("<")) {
+            return null;
+        }
+        return address.toLowerCase(Locale.ROOT);
+    }
+
+    private static Long sizeParam(String text) {
+        for (String param : text.substring(text.indexOf('>') + 1).trim().split("\\s+")) {
+            if (param.regionMatches(true, 0, "SIZE=", 0, 5)) {
+                try {
+                    return Long.parseLong(param.substring(5));
+                } catch (NumberFormatException e) {
+                    return null;
+                }
+            }
+        }
+        return null;
+    }
+
+    private static byte[] stripCr(byte[] line) {
+        if (line.length > 0 && line[line.length - 1] == '\r') {
+            byte[] copy = new byte[line.length - 1];
+            System.arraycopy(line, 0, copy, 0, copy.length);
+            return copy;
+        }
+        return line;
+    }
+
+    private static String ascii(byte[] line) {
+        return new String(line, StandardCharsets.UTF_8);
+    }
+
+    private static String b64(String text) {
+        return Base64.getEncoder().encodeToString(text.getBytes(StandardCharsets.UTF_8));
+    }
+
+    private static String unb64(String text) {
+        try {
+            return new String(Base64.getDecoder().decode(text.trim()), StandardCharsets.UTF_8);
+        } catch (IllegalArgumentException e) {
+            return null;
+        }
+    }
+}

backend/src/main/java/com/mailserver/smtp/SmtpTls.java

@@ -0,0 +1,114 @@
+package com.mailserver.smtp;
+
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.SslContextBuilder;
+import org.bouncycastle.asn1.x500.X500Name;
+import org.bouncycastle.asn1.x509.Extension;
+import org.bouncycastle.asn1.x509.GeneralName;
+import org.bouncycastle.asn1.x509.GeneralNames;
+import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
+import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder;
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.SecureRandom;
+import java.security.cert.X509Certificate;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Base64;
+import java.util.Date;
+
+/**
+ * Certificate for SMTP TLS (STARTTLS and implicit TLS):
+ * <ul>
+ *   <li>{@code cert} and {@code key} given (PEM: certificate chain and the key — PKCS#8, RSA or EC, e.g. from Let's Encrypt) —
+ *       used as is and read again when the files change ({@link ReloadingKeyManager}, checked once a minute);</li>
+ *   <li>otherwise a self-signed certificate for the server hostname, created once in {@code dir} and reused —
+ *       enough for encryption between our own services; other servers deliver over it too (MX delivery does not
+ *       check certificates, RFC 7435 opportunistic TLS).</li>
+ * </ul>
+ */
+public final class SmtpTls {
+
+    private static final Logger log = LoggerFactory.getLogger(SmtpTls.class);
+    static final String CERT_FILE = "smtp-cert.pem";
+    static final String KEY_FILE = "smtp-key.pem";
+    static final Duration RELOAD_CHECK = Duration.ofMinutes(1);
+
+    private SmtpTls() {
+    }
+
+    public static SslContext serverContext(String certFile, String keyFile, Path dir, String hostname) throws Exception {
+        boolean givenCert = certFile != null && !certFile.isBlank();
+        boolean givenKey = keyFile != null && !keyFile.isBlank();
+        if (givenCert != givenKey) {
+            throw new IllegalStateException("TLS: set both the certificate and the key file, or neither");
+        }
+        Path cert;
+        Path key;
+        if (givenCert) {
+            cert = Path.of(certFile);
+            key = Path.of(keyFile);
+            log.info("SMTP TLS: certificate {}", cert);
+        } else {
+            cert = dir.resolve(CERT_FILE);
+            key = dir.resolve(KEY_FILE);
+            if (!Files.exists(cert) || !Files.exists(key)) {
+                selfSigned(hostname, cert, key);
+                log.warn("SMTP TLS: created a self-signed certificate for {} in {}", hostname, dir);
+            } else {
+                log.info("SMTP TLS: self-signed certificate {}", cert);
+            }
+        }
+        // Read again when the files change (a renewed Let's Encrypt certificate) — no restart needed
+        return SslContextBuilder.forServer(new ReloadingKeyManager(cert, key, RELOAD_CHECK, Clock.systemUTC()))
+                .protocols("TLSv1.3", "TLSv1.2")
+                .build();
+    }
+
+    static void selfSigned(String hostname, Path certFile, Path keyFile) throws Exception {
+        KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
+        generator.initialize(2048, new SecureRandom());
+        KeyPair pair = generator.generateKeyPair();
+        X500Name name = new X500Name("CN=" + hostname);
+        Instant now = Instant.now();
+        JcaX509v3CertificateBuilder builder = new JcaX509v3CertificateBuilder(name,
+                new BigInteger(64, new SecureRandom()), Date.from(now.minus(Duration.ofDays(1))),
+                Date.from(now.plus(Duration.ofDays(3650))), name, pair.getPublic());
+        builder.addExtension(Extension.subjectAlternativeName, false,
+                new GeneralNames(new GeneralName(GeneralName.dNSName, hostname)));
+        X509Certificate certificate = new JcaX509CertificateConverter()
+                .getCertificate(builder.build(new JcaContentSignerBuilder("SHA256withRSA").build(pair.getPrivate())));
+
+        Files.createDirectories(keyFile.toAbsolutePath().getParent());
+        write(keyFile, pem("PRIVATE KEY", pair.getPrivate().getEncoded()), true);
+        write(certFile, pem("CERTIFICATE", certificate.getEncoded()), false);
+    }
+
+    private static String pem(String type, byte[] der) {
+        return "-----BEGIN " + type + "-----\n"
+                + Base64.getMimeEncoder(64, new byte[]{'\n'}).encodeToString(der)
+                + "\n-----END " + type + "-----\n";
+    }
+
+    private static void write(Path file, String text, boolean secret) throws IOException {
+        Files.writeString(file, text, StandardCharsets.US_ASCII);
+        if (secret) {
+            try {
+                Files.setPosixFilePermissions(file, PosixFilePermissions.fromString("rw-------"));
+            } catch (UnsupportedOperationException ignored) {
+                // not a POSIX file system
+            }
+        }
+    }
+}

backend/src/main/resources/application-dev.properties

@@ -0,0 +1,14 @@
+# Local development only (./gradlew bootRun --args='--spring.profiles.active=dev'): Postgres from docker-compose.yml
+DB_PORT=5433
+DB_PASSWORD=secret
+JWT_SECRET=dev-only-jwt-secret-not-for-any-real-server-0123456789
+mailserver.domains=mailserver.local
+mailserver.admin.email=admin@mailserver.local
+mailserver.admin.password=admin123
+mailserver.registration.enabled=true
+mailserver.cors.origins=http://localhost:4200
+mailserver.smtp.auth-without-tls=true
+mailserver.dkim.domain=mailserver.local
+mailserver.spf.enabled=false
+mailserver.dmarc.enabled=false
+logging.level.com.mailserver=DEBUG

backend/src/main/resources/application-prod.properties

@@ -1,54 +0,0 @@
-spring.application.name=mail-server
-
-server.port=8080
-
-# R2DBC — реактивный доступ к PostgreSQL
-spring.r2dbc.url=r2dbc:postgresql://localhost:5432/mailserver
-spring.r2dbc.username=mail
-spring.r2dbc.password=secret
-
-# Flyway — миграции базы данных
-spring.flyway.enabled=true
-spring.flyway.url=jdbc:postgresql://localhost:5432/mailserver
-spring.flyway.user=mail
-spring.flyway.password=secret
-spring.flyway.locations=classpath:db/migration
-spring.flyway.baseline-on-migrate=true
-
-# Вложения
-mailserver.attachments.dir=./attachments
-spring.webflux.multipart.max-file-size=10MB
-spring.webflux.multipart.max-request-size=10MB
-
-# SMTP-сервер для приёма входящих писем
-mailserver.smtp.port=3025
-mailserver.smtp.hostname=your-domain.com
-
-# IMAP-сервер (отключён)
-mailserver.imap.enabled=false
-mailserver.imap.port=1143
-mailserver.imap.hostname=localhost
-
-# DKIM — криптографическая подпись писем
-mailserver.dkim.enabled=false
-mailserver.dkim.domain=your-domain.com
-mailserver.dkim.keys-dir=./dkim-keys
-
-# SPF — проверка отправителей через DNS
-mailserver.spf.enabled=false
-mailserver.spf.local-bypass=true
-
-# DMARC — политика обработки писем, не прошедших SPF/DKIM
-mailserver.dmarc.enabled=false
-mailserver.dmarc.local-bypass=true
-
-# SMTP релей — доставка писем на внешнюю почту
-# Порт 25 — стандартный SMTP relay между серверами (VPS)
-mailserver.relay.enabled=true
-mailserver.relay.port=25
-mailserver.relay.starttls=false
-mailserver.relay.auth-enabled=false
-mailserver.relay.username=
-mailserver.relay.password=
-
-logging.level.com.mailserver=INFO

backend/src/main/resources/application.properties

@@ -1,54 +1,101 @@
 spring.application.name=mail-server
-
 server.port=8080
+# behind a proxy (Jambotron Caddy): take scheme/host from X-Forwarded-*, otherwise the browser's own
+# domain looks like another origin to CORS and every API call with an Origin header gets 403
+server.forward-headers-strategy=framework
 
-# R2DBC — реактивный доступ к PostgreSQL
+# Secrets: environment variables, or files in a config tree (file name = variable name, e.g. /run/mail-secrets/DB_PASSWORD).
-spring.r2dbc.url=r2dbc:postgresql://localhost:5432/mailserver
+# No defaults — the server does not start without them (dev profile: application-dev.properties).
-spring.r2dbc.username=mail
+spring.config.import=optional:configtree:${MAILSERVER_SECRETS_DIR:/run/mail-secrets}/
-spring.r2dbc.password=secret
 
-# Flyway — миграции базы данных
+# PostgreSQL: R2DBC for the app, JDBC for Flyway migrations
+spring.r2dbc.url=r2dbc:postgresql://${DB_HOST:localhost}:${DB_PORT:5432}/${DB_NAME:mailserver}
+spring.r2dbc.username=${DB_USER:mail}
+spring.r2dbc.password=${DB_PASSWORD}
 spring.flyway.enabled=true
-spring.flyway.url=jdbc:postgresql://localhost:5432/mailserver
+spring.flyway.url=jdbc:postgresql://${DB_HOST:localhost}:${DB_PORT:5432}/${DB_NAME:mailserver}
-spring.flyway.user=mail
+spring.flyway.user=${DB_USER:mail}
-spring.flyway.password=secret
+spring.flyway.password=${DB_PASSWORD}
 spring.flyway.locations=classpath:db/migration
 spring.flyway.baseline-on-migrate=true
 
-# Вложения
+jwt.secret=${JWT_SECRET}
-mailserver.attachments.dir=./attachments
+
+# Mailboxes of these domains live here; catch-all: mail to any address without its own mailbox here goes into this one mailbox (mail trap), nothing goes outside
+mailserver.domains=${MAIL_DOMAINS:localhost}
+mailserver.catch-all=${MAIL_CATCH_ALL:}
+mailserver.registration.enabled=${MAIL_REGISTRATION:false}
+mailserver.admin.email=${MAIL_ADMIN_EMAIL:}
+mailserver.admin.password=${MAIL_ADMIN_PASSWORD:}
+# Who manages mailboxes (Settings → Mailboxes), comma separated; empty — the first mailbox (admin.email or admin@<first domain>)
+mailserver.admins=${MAIL_ADMINS:}
+# Generated passwords of created mailboxes (first admin, catch-all) are appended here (mode 600); empty — printed to the log once
+mailserver.passwords-file=${MAIL_PASSWORDS_FILE:}
+mailserver.cors.origins=${MAIL_CORS_ORIGINS:}
+
+# Attachments
+mailserver.attachments.dir=${MAIL_ATTACHMENTS_DIR:./attachments}
 spring.webflux.multipart.max-file-size=10MB
 spring.webflux.multipart.max-request-size=10MB
 
-# SMTP-сервер для приёма входящих писем
+# SMTP server (incoming mail and submission). AUTH without TLS only in a closed network (docker network, VM)
-mailserver.smtp.port=3025
+mailserver.smtp.port=${SMTP_PORT:3025}
-mailserver.smtp.hostname=localhost
+mailserver.smtp.hostname=${MAIL_HOSTNAME:localhost}
+mailserver.smtp.auth-without-tls=${SMTP_AUTH_WITHOUT_TLS:false}
+mailserver.smtp.max-message-bytes=26214400
+# TLS (75.1): STARTTLS on the SMTP port; implicit TLS on SMTPS_PORT (465) if set. Certificate: MAIL_TLS_CERT + MAIL_TLS_KEY
+# (PEM, PKCS#8 key), otherwise a self-signed one created once in MAIL_TLS_DIR. MAIL_TLS=false — no TLS
+mailserver.tls.enabled=${MAIL_TLS:true}
+mailserver.tls.cert-file=${MAIL_TLS_CERT:}
+mailserver.tls.key-file=${MAIL_TLS_KEY:}
+mailserver.tls.dir=${MAIL_TLS_DIR:./tls}
+# Web client + API over HTTPS with the same certificate (public compose: 8443 → 443); 0 — only plain HTTP (server.port)
+mailserver.https.port=${HTTPS_PORT:0}
+mailserver.smtps.port=${SMTPS_PORT:0}
 
-# IMAP-сервер для доступа к письмам
+# Outbound: off | mx (straight to recipients' MX, port 25) | smarthost (via a provider, e.g. Resend)
-mailserver.imap.enabled=false
+mailserver.outbound.mode=${OUTBOUND_MODE:off}
-mailserver.imap.port=1143
+mailserver.outbound.host=${OUTBOUND_HOST:}
-mailserver.imap.hostname=localhost
+mailserver.outbound.port=${OUTBOUND_PORT:587}
+mailserver.outbound.username=${OUTBOUND_USERNAME:}
+mailserver.outbound.password=${OUTBOUND_PASSWORD:}
+mailserver.outbound.tls=${OUTBOUND_TLS:starttls}
 
-# DKIM — криптографическая подпись писем
+# IMAP (75.2): STARTTLS on IMAP_PORT, implicit TLS on IMAPS_PORT (993) if set; same certificate as SMTP.
-mailserver.dkim.enabled=false
+# LOGIN only inside TLS unless IMAP_AUTH_WITHOUT_TLS=true (a closed network only)
-mailserver.dkim.domain=localhost
+mailserver.imap.enabled=${IMAP_ENABLED:true}
-mailserver.dkim.keys-dir=./dkim-keys
+mailserver.imap.port=${IMAP_PORT:3143}
+mailserver.imaps.port=${IMAPS_PORT:0}
+mailserver.imap.auth-without-tls=${IMAP_AUTH_WITHOUT_TLS:false}
 
-# SPF — проверка отправителей через DNS
+# DKIM — signing of our mail; DNS record printed to the log at start
-mailserver.spf.enabled=false
+mailserver.dkim.enabled=${DKIM_ENABLED:true}
+mailserver.dkim.domain=${DKIM_DOMAIN:localhost}
+mailserver.dkim.selector=${DKIM_SELECTOR:mail}
+mailserver.dkim.keys-dir=${DKIM_KEYS_DIR:./dkim-keys}
+
+# SPF / DMARC for incoming mail
+mailserver.spf.enabled=${SPF_ENABLED:true}
 mailserver.spf.local-bypass=true
-
+mailserver.dmarc.enabled=${DMARC_ENABLED:true}
-# DMARC — политика обработки писем, не прошедших SPF/DKIM
-mailserver.dmarc.enabled=false
 mailserver.dmarc.local-bypass=true
 
-# SMTP релей — доставка писем на внешнюю почту
+# error responses carry the reason ("No such mailbox", "Sending outside is disabled") for the web client
-# Порт 587 — submission с STARTTLS (для отправки через SMTP-сервер)
+server.error.include-message=always
-mailserver.relay.enabled=true
-mailserver.relay.port=587
-mailserver.relay.starttls=true
-mailserver.relay.auth-enabled=false
-mailserver.relay.username=
-mailserver.relay.password=
 
-logging.level.com.mailserver=DEBUG
+management.endpoints.web.exposure.include=health
+management.endpoint.health.show-details=never
+
+logging.level.com.mailserver=INFO
+
+# Brute-force protection for SMTP AUTH, IMAP login, web login and password change (one counter for all of them):
+# MAX_PER_IP wrong passwords from one IP within WINDOW → the IP is blocked for BLOCK (each next block twice as long,
+# up to MAX_BLOCK); MAX_PER_ACCOUNT wrong passwords to one mailbox from any IPs → the mailbox is blocked for BLOCK,
+# except for IPs that logged in to it before. TRUSTED_IPS (comma-separated) are never blocked by IP
+mailserver.login-guard.enabled=${LOGIN_GUARD:true}
+mailserver.login-guard.max-per-ip=${LOGIN_GUARD_MAX_PER_IP:10}
+mailserver.login-guard.max-per-account=${LOGIN_GUARD_MAX_PER_ACCOUNT:20}
+mailserver.login-guard.window=${LOGIN_GUARD_WINDOW:15m}
+mailserver.login-guard.block=${LOGIN_GUARD_BLOCK:15m}
+mailserver.login-guard.max-block=${LOGIN_GUARD_MAX_BLOCK:24h}
+mailserver.login-guard.trusted-ips=${LOGIN_GUARD_TRUSTED_IPS:}

backend/src/main/resources/db/migration/V2__outbound_queue.sql

@@ -0,0 +1,15 @@
+-- Очередь отправки наружу: письмо хранится как готовые байты (уже с DKIM-подписью) до доставки
+CREATE TABLE outbound_queue (
+    id BIGSERIAL PRIMARY KEY,
+    mail_from VARCHAR(255) NOT NULL,
+    rcpt_to VARCHAR(255) NOT NULL,
+    message BYTEA NOT NULL,
+    status VARCHAR(16) NOT NULL DEFAULT 'PENDING',
+    attempts INTEGER NOT NULL DEFAULT 0,
+    next_attempt_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    last_error VARCHAR(1000),
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    finished_at TIMESTAMP
+);
+
+CREATE INDEX idx_outbound_queue_due ON outbound_queue(next_attempt_at) WHERE status = 'PENDING';

backend/src/main/resources/db/migration/V3__mail_cabinet.sql

@@ -0,0 +1,10 @@
+-- Mail cabinet: several recipients and copy, system vs own folders
+ALTER TABLE messages ALTER COLUMN recipient_email TYPE TEXT;
+ALTER TABLE messages ADD COLUMN cc_email TEXT;
+
+ALTER TABLE folders ADD COLUMN is_system BOOLEAN NOT NULL DEFAULT FALSE;
+UPDATE folders SET is_system = TRUE WHERE name IN ('INBOX', 'Sent', 'Drafts', 'Trash', 'Spam');
+CREATE UNIQUE INDEX idx_folders_user_name ON folders(user_id, LOWER(name));
+
+-- the attachments entity always had content_id (inline images, cid:) — the column was missing
+ALTER TABLE attachments ADD COLUMN content_id VARCHAR(255);

backend/src/main/resources/db/migration/V4__imap.sql

@@ -0,0 +1,43 @@
+-- IMAP (75.2): UIDs per folder, IMAP flags, the original message text
+
+-- UIDVALIDITY: never changes for a folder; UIDNEXT: the next UID to give out
+ALTER TABLE folders ADD COLUMN uid_validity BIGINT NOT NULL DEFAULT (EXTRACT(EPOCH FROM now())::BIGINT);
+ALTER TABLE folders ADD COLUMN uid_next BIGINT NOT NULL DEFAULT 1;
+
+-- UID inside the folder; strictly increasing — a message moved into a folder gets a new, larger UID
+ALTER TABLE messages ADD COLUMN uid BIGINT;
+ALTER TABLE messages ADD COLUMN is_answered BOOLEAN NOT NULL DEFAULT FALSE;
+ALTER TABLE messages ADD COLUMN is_deleted BOOLEAN NOT NULL DEFAULT FALSE;
+
+UPDATE messages m SET uid = numbered.n
+FROM (SELECT id, ROW_NUMBER() OVER (PARTITION BY folder_id ORDER BY received_at, id) AS n FROM messages) numbered
+WHERE m.id = numbered.id;
+
+UPDATE folders f SET uid_next = COALESCE((SELECT MAX(uid) FROM messages WHERE folder_id = f.id), 0) + 1;
+
+ALTER TABLE messages ALTER COLUMN uid SET NOT NULL;
+CREATE UNIQUE INDEX idx_messages_folder_uid ON messages(folder_id, uid);
+
+-- The UID is given out by the database, so every path that stores or moves a message (SMTP, web client, IMAP)
+-- gets it right without knowing about IMAP
+CREATE FUNCTION assign_message_uid() RETURNS trigger AS $$
+BEGIN
+    UPDATE folders SET uid_next = uid_next + 1 WHERE id = NEW.folder_id RETURNING uid_next - 1 INTO NEW.uid;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER messages_uid_on_insert BEFORE INSERT ON messages
+    FOR EACH ROW EXECUTE FUNCTION assign_message_uid();
+
+-- The web client saves the whole row (folder_id included) — only a real move gets a new UID
+CREATE TRIGGER messages_uid_on_move BEFORE UPDATE OF folder_id ON messages
+    FOR EACH ROW WHEN (NEW.folder_id IS DISTINCT FROM OLD.folder_id) EXECUTE FUNCTION assign_message_uid();
+
+-- The message exactly as received (SMTP) or appended (IMAP APPEND); for messages without it the server builds
+-- the MIME text once from the stored fields and keeps it here, so sizes and bytes never change between fetches.
+-- Removed when a draft changes.
+CREATE TABLE message_sources (
+    message_id BIGINT PRIMARY KEY REFERENCES messages(id) ON DELETE CASCADE,
+    raw BYTEA NOT NULL
+);

backend/src/test/java/com/mailserver/config/DataInitializerTest.java

@@ -0,0 +1,26 @@
+package com.mailserver.config;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.PosixFilePermissions;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class DataInitializerTest {
+
+    @Test
+    void generatedPasswordsAreAppendedToAFileOnlyTheOwnerReads(@TempDir Path dir) throws Exception {
+        Path file = dir.resolve("data/initial-passwords.txt");
+
+        DataInitializer.appendPassword(file, "admin@mail.test", "secret-1");
+        DataInitializer.appendPassword(file, "trap@mail.test", "secret-2");
+
+        assertThat(Files.readAllLines(file)).hasSize(2);
+        assertThat(Files.readAllLines(file).get(0)).endsWith(" admin@mail.test secret-1");
+        assertThat(Files.readAllLines(file).get(1)).endsWith(" trap@mail.test secret-2");
+        assertThat(PosixFilePermissions.toString(Files.getPosixFilePermissions(file))).isEqualTo("rw-------");
+    }
+}

backend/src/test/java/com/mailserver/config/HttpsConfigTest.java

@@ -0,0 +1,45 @@
+package com.mailserver.config;
+
+import com.mailserver.smtp.SmtpTls;
+import io.netty.handler.ssl.SslContextBuilder;
+import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.HttpHandler;
+import reactor.core.publisher.Mono;
+import reactor.netty.http.client.HttpClient;
+
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/** https://mail.jambocheck.com: the web client over HTTPS with the mail certificate. */
+class HttpsConfigTest {
+
+    @Test
+    void servesTheWebAppOverTls(@TempDir Path dir) throws Exception {
+        MailServerConfig.SmtpTlsContext tls = new MailServerConfig.SmtpTlsContext(SmtpTls.serverContext("", "", dir, "localhost"));
+        HttpHandler handler = (request, response) -> {
+            response.setStatusCode(HttpStatus.OK);
+            return response.writeWith(Mono.just(DefaultDataBufferFactory.sharedInstance
+                    .wrap(("hello " + request.getURI().getScheme()).getBytes(StandardCharsets.UTF_8))));
+        };
+        io.netty.handler.ssl.SslContext trustAll = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();
+        HttpsConfig.HttpsServer server = new HttpsConfig.HttpsServer(handler, tls, "127.0.0.1", 0);
+        server.start();
+        try {
+            assertThat(server.isRunning()).isTrue();
+            String body = HttpClient.create()
+                    .secure(spec -> spec.sslContext(trustAll))
+                    .get().uri("https://127.0.0.1:" + server.port() + "/")
+                    .responseContent().aggregate().asString().block();
+            assertThat(body).isEqualTo("hello https");
+        } finally {
+            server.stop();
+        }
+        assertThat(server.isRunning()).isFalse();
+    }
+}

backend/src/test/java/com/mailserver/config/LoginGuardConfigTest.java

@@ -0,0 +1,46 @@
+package com.mailserver.config;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
+
+import java.net.InetSocketAddress;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class LoginGuardConfigTest {
+
+    private final LoginGuardConfig.TrustedProxyHeaderTransformer transformer = new LoginGuardConfig.TrustedProxyHeaderTransformer();
+
+    private ServerHttpRequest from(String peer) {
+        return MockServerHttpRequest.post("/api/login")
+                .remoteAddress(new InetSocketAddress(peer, 40000))
+                .header("X-Forwarded-For", "198.51.100.9")
+                .header("X-Forwarded-Proto", "https")
+                .build();
+    }
+
+    @Test
+    void forwardedForIsBelievedFromAPrivateProxy() {
+        ServerHttpRequest request = transformer.apply(from("172.18.0.5"));
+        assertThat(request.getRemoteAddress().getHostString()).isEqualTo("198.51.100.9");
+        assertThat(request.getURI().getScheme()).isEqualTo("https");
+    }
+
+    @Test
+    void forwardedForFromTheInternetIsDropped() {
+        ServerHttpRequest request = transformer.apply(from("203.0.113.7"));
+        assertThat(request.getRemoteAddress().getAddress().getHostAddress()).isEqualTo("203.0.113.7");
+        assertThat(request.getHeaders().containsKey("X-Forwarded-For")).isFalse();
+    }
+
+    @Test
+    void privateRanges() {
+        for (String ip : new String[]{"127.0.0.1", "10.30.0.13", "172.16.0.1", "192.168.1.1", "fd00::1", "::1", "fe80::1"}) {
+            assertThat(LoginGuardConfig.privatePeer(new InetSocketAddress(ip, 1))).as(ip).isTrue();
+        }
+        for (String ip : new String[]{"103.109.235.154", "172.32.0.1", "2001:db8::1", "8.8.8.8"}) {
+            assertThat(LoginGuardConfig.privatePeer(new InetSocketAddress(ip, 1))).as(ip).isFalse();
+        }
+    }
+}

backend/src/test/java/com/mailserver/controller/AuthenticationControllerTest.java

@@ -0,0 +1,81 @@
+package com.mailserver.controller;
+
+import com.mailserver.config.MailDomains;
+import com.mailserver.domain.User;
+import com.mailserver.dto.LoginRequest;
+import com.mailserver.security.LoginGuard;
+import com.mailserver.service.MailService;
+import com.mailserver.service.UserService;
+import com.mailserver.util.JwtUtils;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
+import reactor.core.publisher.Mono;
+
+import java.net.InetSocketAddress;
+import java.time.Duration;
+import java.util.Map;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class AuthenticationControllerTest {
+
+    private final UserService users = mock(UserService.class);
+    private final JwtUtils jwt = mock(JwtUtils.class);
+    private final LoginGuard guard = new LoginGuard(new LoginGuard.Settings(true, 3, 100, Duration.ofMinutes(15),
+            Duration.ofMinutes(15), Duration.ofHours(24), Duration.ofDays(30), Set.of(), Duration.ZERO));
+    private final AuthenticationController controller = new AuthenticationController(users, mock(MailService.class), jwt,
+            mock(MailDomains.class), false, guard, mock(com.mailserver.config.MailAdmins.class));
+
+    private final User alice = new User();
+
+    AuthenticationControllerTest() {
+        alice.setEmail("alice@x.test");
+        alice.setPassword("hash");
+        when(users.findByEmail("alice@x.test")).thenReturn(Mono.just(alice));
+        when(users.findByEmail("ghost@x.test")).thenReturn(Mono.empty());
+        when(users.checkPassword(eq(alice), anyString())).thenAnswer(i -> "secret".equals(i.getArgument(1)));
+        when(jwt.generateToken(any())).thenReturn("token");
+    }
+
+    private ResponseEntity<?> login(String ip, String email, String password) {
+        LoginRequest request = new LoginRequest();
+        request.setEmail(email);
+        request.setPassword(password);
+        MockServerHttpRequest http = MockServerHttpRequest.post("/api/login")
+                .remoteAddress(new InetSocketAddress(ip, 40000)).build();
+        return controller.login(Mono.just(request), http).block();
+    }
+
+    @Test
+    void unknownMailboxAndWrongPasswordLookTheSameAndBothCount() {
+        assertThat(login("1.2.3.4", "ghost@x.test", "x").getBody()).isEqualTo(Map.of("error", "Invalid credentials"));
+        assertThat(login("1.2.3.4", "alice@x.test", "x").getBody()).isEqualTo(Map.of("error", "Invalid credentials"));
+        login("1.2.3.4", "alice@x.test", "y");
+
+        ResponseEntity<?> blocked = login("1.2.3.4", "alice@x.test", "secret");
+        assertThat(blocked.getStatusCode()).isEqualTo(HttpStatus.TOO_MANY_REQUESTS);
+        assertThat(blocked.getHeaders().getFirst("Retry-After")).isEqualTo("900");
+        assertThat(blocked.getBody()).isEqualTo(Map.of("error", "Too many failed logins, try again in 15 min"));
+
+        assertThat(login("5.6.7.8", "alice@x.test", "secret").getStatusCode()).isEqualTo(HttpStatus.OK);
+    }
+
+    @Test
+    void blockedAttemptDoesNotCheckThePassword() {
+        for (int i = 0; i < 3; i++) {
+            login("1.2.3.4", "ghost@x.test", "x");
+        }
+        login("1.2.3.4", "alice@x.test", "secret");
+        verify(users, never()).checkPassword(any(), eq("secret"));
+    }
+}

backend/src/test/java/com/mailserver/controller/MailControllerTest.java

@@ -0,0 +1,18 @@
+package com.mailserver.controller;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class MailControllerTest {
+
+    @Test
+    void attachmentNameCannotLeaveTheFolder() {
+        assertThat(MailController.safeFilename("../../etc/passwd")).isEqualTo("passwd");
+        assertThat(MailController.safeFilename("..\\..\\boot.ini")).isEqualTo("boot.ini");
+        assertThat(MailController.safeFilename("..")).isEqualTo("file");
+        assertThat(MailController.safeFilename("a\"b\r\n.txt")).isEqualTo("ab.txt");
+        assertThat(MailController.safeFilename(null)).isEqualTo("file");
+        assertThat(MailController.safeFilename("report 2026.pdf")).isEqualTo("report 2026.pdf");
+    }
+}

backend/src/test/java/com/mailserver/controller/MailboxAdminControllerTest.java

@@ -0,0 +1,143 @@
+package com.mailserver.controller;
+
+import com.mailserver.config.MailAdmins;
+import com.mailserver.config.MailDomains;
+import com.mailserver.domain.User;
+import com.mailserver.service.MailService;
+import com.mailserver.service.UserService;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.server.ResponseStatusException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/** Settings → Mailboxes: only administrators; mailboxes only in our domains; a generated password comes back once. */
+class MailboxAdminControllerTest {
+
+    private final UserService users = mock(UserService.class);
+    private final MailService mail = mock(MailService.class);
+    private final MailDomains domains = new MailDomains("jambocheck.com", "");
+    private final MailAdmins admins = new MailAdmins("", "", domains);
+    private final com.mailserver.util.JwtUtils jwt = mock(com.mailserver.util.JwtUtils.class);
+    private final MailboxAdminController controller = new MailboxAdminController(users, mail, domains, admins, jwt);
+
+    private final User admin = user(1L, "admin@jambocheck.com");
+    private final User alice = user(2L, "alice@jambocheck.com");
+
+    MailboxAdminControllerTest() {
+        when(mail.usedBytes(anyLong())).thenReturn(Mono.just(0L));
+        when(users.all()).thenReturn(Flux.just(alice, admin));
+        when(users.byId(1L)).thenReturn(Mono.just(admin));
+        when(users.byId(2L)).thenReturn(Mono.just(alice));
+        when(users.byId(99L)).thenReturn(Mono.empty());
+        when(users.register(anyString(), anyString(), any())).thenAnswer(i -> Mono.just(user(3L, i.getArgument(0))));
+        when(users.setPassword(any(), anyString())).thenAnswer(i -> Mono.just((User) i.getArgument(0)));
+        when(users.setActive(any(), any(Boolean.class))).thenAnswer(i -> {
+            User u = i.getArgument(0);
+            u.setActive(i.getArgument(1));
+            return Mono.just(u);
+        });
+    }
+
+    @Test
+    void administratorIsTheFirstMailboxByDefault() {
+        assertThat(admins.isAdmin("ADMIN@jambocheck.com")).isTrue();
+        assertThat(admins.isAdmin("alice@jambocheck.com")).isFalse();
+        assertThat(new MailAdmins("ops@jambocheck.com, root@jambocheck.com", "admin@jambocheck.com", domains).isAdmin("admin@jambocheck.com")).isFalse();
+    }
+
+    @Test
+    void listsMailboxesSortedForAnAdministratorOnly() {
+        List<MailboxAdminController.MailboxView> list = controller.list(as("admin@jambocheck.com")).collectList().block();
+        assertThat(list).extracting(MailboxAdminController.MailboxView::email).containsExactly("admin@jambocheck.com", "alice@jambocheck.com");
+        assertThat(list.get(0).admin()).isTrue();
+
+        assertThat(status(() -> controller.list(as("alice@jambocheck.com")).collectList().block())).isEqualTo(HttpStatus.FORBIDDEN);
+    }
+
+    @Test
+    void createsReservedNamesWithAGeneratedPasswordShownOnce() {
+        var created = controller.create(as("admin@jambocheck.com"),
+                Mono.just(new MailboxAdminController.CreateRequest(" No-Reply@JamboCheck.com ", "Jambotron", ""))).block();
+
+        assertThat(created.mailbox().email()).isEqualTo("no-reply@jambocheck.com");
+        assertThat(created.password()).hasSizeGreaterThanOrEqualTo(20);
+        verify(users).register(eq("no-reply@jambocheck.com"), eq(created.password()), eq("Jambotron"));
+
+        var chosen = controller.create(as("admin@jambocheck.com"),
+                Mono.just(new MailboxAdminController.CreateRequest("monitor@jambocheck.com", null, "long-enough-1"))).block();
+        assertThat(chosen.password()).isNull();
+    }
+
+    @Test
+    void refusesOtherDomainsBadAddressesShortPasswordsAndNonAdmins() {
+        assertThat(status(() -> create("admin@jambocheck.com", "x@gmail.com", ""))).isEqualTo(HttpStatus.BAD_REQUEST);
+        assertThat(status(() -> create("admin@jambocheck.com", "bad address@jambocheck.com", ""))).isEqualTo(HttpStatus.BAD_REQUEST);
+        assertThat(status(() -> create("admin@jambocheck.com", "x@jambocheck.com", "short"))).isEqualTo(HttpStatus.BAD_REQUEST);
+        assertThat(status(() -> create("alice@jambocheck.com", "x@jambocheck.com", ""))).isEqualTo(HttpStatus.FORBIDDEN);
+        verify(users, never()).register(anyString(), anyString(), any());
+
+        when(users.register(eq("alice@jambocheck.com"), anyString(), any())).thenReturn(Mono.error(new IllegalArgumentException("exists")));
+        assertThat(status(() -> create("admin@jambocheck.com", "alice@jambocheck.com", ""))).isEqualTo(HttpStatus.CONFLICT);
+    }
+
+    @Test
+    void newPasswordAndSwitchOffButNotYourself() {
+        var reset = controller.password(as("admin@jambocheck.com"), 2L, Mono.just(new MailboxAdminController.PasswordRequest(null))).block();
+        assertThat(reset.password()).isNotBlank();
+        verify(users).setPassword(alice, reset.password());
+
+        assertThat(controller.active(as("admin@jambocheck.com"), 2L, Mono.just(new MailboxAdminController.ActiveRequest(false))).block().active()).isFalse();
+        assertThat(status(() -> controller.active(as("admin@jambocheck.com"), 1L, Mono.just(new MailboxAdminController.ActiveRequest(false))).block()))
+                .isEqualTo(HttpStatus.BAD_REQUEST);
+    }
+
+    @Test
+    void administratorOpensAnyMailboxOthersCanNot() {
+        when(jwt.generateToken("alice@jambocheck.com")).thenReturn("alice-token");
+
+        var session = controller.open(as("admin@jambocheck.com"), 2L).block();
+        assertThat(session.getEmail()).isEqualTo("alice@jambocheck.com");
+        assertThat(session.getToken()).isEqualTo("alice-token");
+
+        assertThat(status(() -> controller.open(as("alice@jambocheck.com"), 1L).block())).isEqualTo(HttpStatus.FORBIDDEN);
+        assertThat(status(() -> controller.open(as("admin@jambocheck.com"), 99L).block())).isEqualTo(HttpStatus.NOT_FOUND);
+    }
+
+    private MailboxAdminController.Created create(String me, String email, String password) {
+        return controller.create(as(me), Mono.just(new MailboxAdminController.CreateRequest(email, null, password))).block();
+    }
+
+    private static Mono<Authentication> as(String email) {
+        return Mono.just(new UsernamePasswordAuthenticationToken(email, null, List.of()));
+    }
+
+    private static HttpStatus status(Runnable call) {
+        Throwable error = org.assertj.core.api.Assertions.catchThrowable(call::run);
+        assertThat(error).isInstanceOf(ResponseStatusException.class);
+        return HttpStatus.valueOf(((ResponseStatusException) error).getStatusCode().value());
+    }
+
+    private static User user(Long id, String email) {
+        User user = new User();
+        user.setId(id);
+        user.setEmail(email);
+        user.setPassword("hash");
+        return user;
+    }
+}

backend/src/test/java/com/mailserver/delivery/DeliveryWorkerTest.java

@@ -0,0 +1,88 @@
+package com.mailserver.delivery;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class DeliveryWorkerTest {
+
+    private OutboundRepository repository;
+    private final List<String> bounces = new ArrayList<>();
+    private SmtpDeliveryClient.Result next;
+
+    @BeforeEach
+    void setUp() {
+        repository = mock(OutboundRepository.class);
+        when(repository.save(any())).thenAnswer(call -> Mono.just(call.getArgument(0)));
+    }
+
+    private DeliveryWorker worker() {
+        SmtpDeliveryClient client = new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(SmtpDeliveryClient.Mode.MX,
+                "", 0, "", "", SmtpDeliveryClient.Tls.NONE, "mx", 1000, 25), domain -> List.of("mx")) {
+            @Override
+            public Result deliver(String from, String recipient, byte[] message) {
+                return next;
+            }
+        };
+        return new DeliveryWorker(repository, client, (message, reason) -> bounces.add(message.getRcptTo() + ": " + reason));
+    }
+
+    private static OutboundMessage queued() {
+        OutboundMessage message = new OutboundMessage();
+        message.setId(1L);
+        message.setMailFrom("alice@ours.test");
+        message.setRcptTo("bob@theirs.test");
+        message.setMessage(new byte[]{1});
+        return message;
+    }
+
+    @Test
+    void deliveredIsDone() {
+        next = new SmtpDeliveryClient.Result(SmtpDeliveryClient.Outcome.DELIVERED, "mx");
+        OutboundMessage message = queued();
+        worker().attempt(message, Instant.EPOCH);
+        assertThat(message.getStatus()).isEqualTo(OutboundMessage.DELIVERED);
+        assertThat(message.getLastError()).isNull();
+        assertThat(bounces).isEmpty();
+    }
+
+    @Test
+    void temporaryFailureIsRetriedWithGrowingPausesThenBounced() {
+        next = new SmtpDeliveryClient.Result(SmtpDeliveryClient.Outcome.TEMPORARY, "451 greylisted");
+        OutboundMessage message = queued();
+        DeliveryWorker worker = worker();
+        Instant now = Instant.EPOCH;
+        List<Duration> pauses = new ArrayList<>();
+        for (int i = 0; i < DeliveryWorker.RETRY_PAUSES.size(); i++) {
+            worker.attempt(message, now);
+            assertThat(message.getStatus()).isEqualTo(OutboundMessage.PENDING);
+            pauses.add(Duration.between(now, message.getNextAttemptAt()));
+            now = message.getNextAttemptAt();
+        }
+        assertThat(pauses).isEqualTo(DeliveryWorker.RETRY_PAUSES);
+
+        worker.attempt(message, now);
+        assertThat(message.getStatus()).isEqualTo(OutboundMessage.FAILED);
+        assertThat(bounces).singleElement().asString().contains("gave up after 8 attempts").contains("451 greylisted");
+    }
+
+    @Test
+    void permanentFailureBouncesAtOnce() {
+        next = new SmtpDeliveryClient.Result(SmtpDeliveryClient.Outcome.PERMANENT, "550 no such user");
+        OutboundMessage message = queued();
+        worker().attempt(message, Instant.EPOCH);
+        assertThat(message.getStatus()).isEqualTo(OutboundMessage.FAILED);
+        assertThat(message.getLastError()).isEqualTo("550 no such user");
+        assertThat(bounces).containsExactly("bob@theirs.test: 550 no such user");
+    }
+}

backend/src/test/java/com/mailserver/delivery/SmtpDeliveryClientTest.java

@@ -0,0 +1,109 @@
+package com.mailserver.delivery;
+
+import com.icegreen.greenmail.util.GreenMail;
+import com.icegreen.greenmail.util.ServerSetup;
+import jakarta.mail.internet.MimeMessage;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.net.ServerSocket;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SmtpDeliveryClientTest {
+
+    private static final String MESSAGE = "From: alice@ours.test\r\nTo: bob@theirs.test\r\nSubject: Hi\r\n"
+            + "DKIM-Signature: v=1; a=rsa-sha256; d=ours.test; s=mail; h=from; bh=x; b=y\r\n\r\nbody\r\n.dot line\r\n";
+
+    private GreenMail greenMail;
+
+    @BeforeEach
+    void start() {
+        greenMail = new GreenMail(new ServerSetup(0, "127.0.0.1", ServerSetup.PROTOCOL_SMTP));
+        greenMail.setUser("relay-user", "relay-pass");
+        greenMail.start();
+    }
+
+    @AfterEach
+    void stop() {
+        greenMail.stop();
+    }
+
+    private int port() {
+        return greenMail.getSmtp().getPort();
+    }
+
+    private SmtpDeliveryClient mxClient(int mxPort, List<String> hosts) {
+        return new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(SmtpDeliveryClient.Mode.MX, "", 0, "", "",
+                SmtpDeliveryClient.Tls.NONE, "mx.ours.test", 5000, mxPort), domain -> hosts);
+    }
+
+    @Test
+    void deliversToTheMxAndKeepsTheBytesUnchanged() throws Exception {
+        SmtpDeliveryClient.Result result = mxClient(port(), List.of("127.0.0.1"))
+                .deliver("alice@ours.test", "bob@theirs.test", MESSAGE.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(result.outcome()).isEqualTo(SmtpDeliveryClient.Outcome.DELIVERED);
+        MimeMessage[] received = greenMail.getReceivedMessages();
+        assertThat(received).hasSize(1);
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        received[0].writeTo(out);
+        // GreenMail adds its Received/Return-Path; everything we sent is there byte for byte (DKIM stays valid)
+        assertThat(out.toString(StandardCharsets.UTF_8)).contains(MESSAGE.stripTrailing());
+    }
+
+    @Test
+    void triesTheNextMxWhenTheFirstDoesNotAnswer() throws Exception {
+        int closed;
+        try (ServerSocket socket = new ServerSocket(0)) {
+            closed = socket.getLocalPort();
+        }
+        // first "host" refuses the connection, second is GreenMail — both on 127.0.0.1, so use two clients' ports:
+        SmtpDeliveryClient.Result refused = mxClient(closed, List.of("127.0.0.1"))
+                .deliver("alice@ours.test", "bob@theirs.test", MESSAGE.getBytes(StandardCharsets.UTF_8));
+        assertThat(refused.outcome()).isEqualTo(SmtpDeliveryClient.Outcome.TEMPORARY);
+
+        SmtpDeliveryClient.Result fallback = mxClient(port(), List.of("unreachable.invalid", "127.0.0.1"))
+                .deliver("alice@ours.test", "bob@theirs.test", MESSAGE.getBytes(StandardCharsets.UTF_8));
+        assertThat(fallback.outcome()).isEqualTo(SmtpDeliveryClient.Outcome.DELIVERED);
+    }
+
+    @Test
+    void domainWithoutMailServerIsAPermanentFailure() {
+        SmtpDeliveryClient.Result result = mxClient(port(), List.of())
+                .deliver("alice@ours.test", "bob@nowhere.test", MESSAGE.getBytes(StandardCharsets.UTF_8));
+        assertThat(result.outcome()).isEqualTo(SmtpDeliveryClient.Outcome.PERMANENT);
+    }
+
+    @Test
+    void dnsTroubleIsTemporary() {
+        SmtpDeliveryClient client = new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(SmtpDeliveryClient.Mode.MX,
+                "", 0, "", "", SmtpDeliveryClient.Tls.NONE, "mx.ours.test", 5000, port()),
+                domain -> { throw new SmtpDeliveryClient.TemporaryDnsException("SERVFAIL"); });
+        assertThat(client.deliver("a@ours.test", "b@theirs.test", MESSAGE.getBytes()).outcome())
+                .isEqualTo(SmtpDeliveryClient.Outcome.TEMPORARY);
+    }
+
+    @Test
+    void sendsThroughASmarthostWithLogin() {
+        SmtpDeliveryClient client = new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(SmtpDeliveryClient.Mode.SMARTHOST,
+                "127.0.0.1", port(), "relay-user", "relay-pass", SmtpDeliveryClient.Tls.NONE, "mx.ours.test", 5000, 25));
+
+        assertThat(client.deliver("alice@ours.test", "bob@theirs.test", MESSAGE.getBytes()).outcome())
+                .isEqualTo(SmtpDeliveryClient.Outcome.DELIVERED);
+        assertThat(greenMail.getReceivedMessages()).hasSize(1);
+    }
+
+    @Test
+    void offModeSendsNothing() {
+        SmtpDeliveryClient client = new SmtpDeliveryClient(new SmtpDeliveryClient.Settings(SmtpDeliveryClient.Mode.OFF,
+                "", 0, "", "", SmtpDeliveryClient.Tls.NONE, "mx.ours.test", 5000, 25));
+        assertThat(client.deliver("a@ours.test", "b@theirs.test", MESSAGE.getBytes()).outcome())
+                .isEqualTo(SmtpDeliveryClient.Outcome.PERMANENT);
+        assertThat(greenMail.getReceivedMessages()).isEmpty();
+    }
+}

backend/src/test/java/com/mailserver/imap/ImapServerTest.java

@@ -0,0 +1,373 @@
+package com.mailserver.imap;
+
+import com.mailserver.smtp.SmtpTls;
+import jakarta.mail.BodyPart;
+import jakarta.mail.Flags;
+import jakarta.mail.Folder;
+import jakarta.mail.Message;
+import jakarta.mail.Multipart;
+import jakarta.mail.Session;
+import jakarta.mail.Store;
+import jakarta.mail.UIDFolder;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import jakarta.mail.search.SubjectTerm;
+import org.eclipse.angus.mail.imap.AppendUID;
+import org.eclipse.angus.mail.imap.IMAPFolder;
+import com.mailserver.security.LoginGuard;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocket;
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.X509TrustManager;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.security.cert.X509Certificate;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ImapServerTest {
+
+    static final String PLAIN = """
+            From: Bob <bob@elsewhere.test>
+            To: alice@example.test
+            Subject: Hello Alice
+            Date: Thu, 05 Nov 2026 10:00:00 +0000
+            Message-ID: <hello@elsewhere.test>
+            Content-Type: text/plain; charset=utf-8
+
+            Hi there, line one.
+            Line two.
+            """;
+
+    static final String WITH_FILE = """
+            From: =?UTF-8?B?0JDQvdC90LA=?= <anna@elsewhere.test>
+            To: alice@example.test
+            Subject: =?UTF-8?B?0J7RgtGH0ZHRgg==?=
+            Date: Thu, 05 Nov 2026 11:00:00 +0000
+            MIME-Version: 1.0
+            Content-Type: multipart/mixed; boundary="b1"
+
+            preamble
+            --b1
+            Content-Type: text/plain; charset=utf-8
+
+            See the report.
+            --b1
+            Content-Type: application/pdf; name="report.pdf"
+            Content-Disposition: attachment; filename="report.pdf"
+            Content-Transfer-Encoding: base64
+
+            JVBERi0xLjQgdGVzdA==
+            --b1--
+            """;
+
+    @TempDir
+    Path tlsDir;
+
+    private MemoryImapStore store;
+    private ImapServer server;
+
+    @BeforeEach
+    void start() throws Exception {
+        store = new MemoryImapStore();
+        store.deliver("INBOX", PLAIN);
+        store.deliver("INBOX", WITH_FILE);
+        server = new ImapServer(new ImapServer.Settings("127.0.0.1", 0, "mx.example.test", false,
+                SmtpTls.serverContext(null, null, tlsDir, "mx.example.test"), false, 1_000_000,
+                Duration.ofMinutes(5), Duration.ofMillis(200)), store);
+        server.start();
+    }
+
+    @AfterEach
+    void stop() {
+        server.stop();
+    }
+
+    private Store connect() throws Exception {
+        Properties props = new Properties();
+        props.put("mail.imap.host", "127.0.0.1");
+        props.put("mail.imap.port", String.valueOf(server.port()));
+        props.put("mail.imap.starttls.enable", "true");
+        props.put("mail.imap.starttls.required", "true");
+        props.put("mail.imap.ssl.trust", "*");
+        props.put("mail.imap.ssl.checkserveridentity", "false");
+        Store imap = Session.getInstance(props).getStore("imap");
+        imap.connect("alice@example.test", "secret");
+        return imap;
+    }
+
+    @Test
+    void realClientReadsFoldersMessagesAndAttachments() throws Exception {
+        try (Store imap = connect()) {
+            List<String> names = Arrays.stream(imap.getDefaultFolder().list("*")).map(Folder::getFullName).toList();
+            assertThat(names).contains("INBOX", "Drafts", "Sent", "Spam", "Trash");
+
+            IMAPFolder inbox = (IMAPFolder) imap.getFolder("INBOX");
+            inbox.open(Folder.READ_WRITE);
+            assertThat(inbox.getMessageCount()).isEqualTo(2);
+            assertThat(inbox.getUnreadMessageCount()).isEqualTo(2);
+
+            Message first = inbox.getMessage(1);
+            assertThat(first.getSubject()).isEqualTo("Hello Alice");
+            assertThat(((InternetAddress) first.getFrom()[0]).getPersonal()).isEqualTo("Bob");
+            assertThat(first.getContent().toString()).contains("Line two.");
+            assertThat(first.isSet(Flags.Flag.SEEN)).isTrue(); // BODY[] without PEEK
+
+            Message second = inbox.getMessage(2);
+            assertThat(second.getSubject()).isEqualTo("Отчёт");
+            assertThat(((InternetAddress) second.getFrom()[0]).getPersonal()).isEqualTo("Анна");
+            Multipart parts = (Multipart) second.getContent(); // BODYSTRUCTURE, then BODY[1] and BODY[2]
+            assertThat(parts.getCount()).isEqualTo(2);
+            assertThat(parts.getBodyPart(0).getContent().toString()).contains("See the report.");
+            BodyPart file = parts.getBodyPart(1);
+            assertThat(file.getFileName()).isEqualTo("report.pdf");
+            assertThat(new String(file.getInputStream().readAllBytes(), StandardCharsets.US_ASCII)).isEqualTo("%PDF-1.4 test");
+
+            assertThat(inbox.search(new SubjectTerm("hello"))).hasSize(1);
+            assertThat(inbox.getUID(first)).isEqualTo(1);
+            assertThat(inbox.getMessageByUID(2).getSubject()).isEqualTo("Отчёт");
+        }
+    }
+
+    @Test
+    void appendCopyMoveAndExpunge() throws Exception {
+        try (Store imap = connect()) {
+            IMAPFolder sent = (IMAPFolder) imap.getFolder("Sent");
+            MimeMessage outgoing = new MimeMessage(Session.getInstance(new Properties()));
+            outgoing.setFrom(new InternetAddress("alice@example.test"));
+            outgoing.setRecipient(Message.RecipientType.TO, new InternetAddress("bob@elsewhere.test"));
+            outgoing.setSubject("Sent from Thunderbird");
+            outgoing.setText("body");
+            AppendUID[] appended = sent.appendUIDMessages(new Message[]{outgoing});
+            assertThat(appended[0].uid).isEqualTo(1);
+            assertThat(appended[0].uidvalidity).isEqualTo(store.box("Sent").uidValidity());
+
+            IMAPFolder inbox = (IMAPFolder) imap.getFolder("INBOX");
+            inbox.open(Folder.READ_WRITE);
+            inbox.copyMessages(new Message[]{inbox.getMessage(1)}, imap.getFolder("Trash"));
+            inbox.moveMessages(new Message[]{inbox.getMessage(2)}, imap.getFolder("Spam"));
+            inbox.close(false); // JavaMail counts EXPUNGEd messages until the folder is opened again
+            inbox.open(Folder.READ_WRITE);
+            assertThat(inbox.getMessageCount()).isEqualTo(1);
+
+            inbox.getMessage(1).setFlag(Flags.Flag.DELETED, true);
+            inbox.expunge();
+            assertThat(inbox.getMessageCount()).isZero();
+        }
+        assertThat(store.entries(store.box("Trash").id())).hasSize(1);
+        assertThat(store.entries(store.box("Spam").id())).hasSize(1);
+        assertThat(store.entries(store.box("Sent").id())).hasSize(1);
+    }
+
+    @Test
+    void createRenameAndDeleteFolders() throws Exception {
+        try (Store imap = connect()) {
+            Folder projects = imap.getFolder("Проекты");
+            assertThat(projects.create(Folder.HOLDS_MESSAGES)).isTrue();
+            assertThat(Arrays.stream(imap.getDefaultFolder().list("*")).map(Folder::getFullName)).contains("Проекты");
+            assertThat(projects.renameTo(imap.getFolder("Archive"))).isTrue();
+            assertThat(imap.getFolder("Archive").delete(false)).isTrue();
+            assertThat(imap.getFolder("Archive").exists()).isFalse();
+        }
+    }
+
+    @Test
+    void wrongPasswordsCloseTheConnectionAndTheGuardBlocksTheIp() throws Exception {
+        server.stop();
+        LoginGuard guard = new LoginGuard(new LoginGuard.Settings(true, 4, 100, Duration.ofMinutes(15),
+                Duration.ofMinutes(15), Duration.ofHours(24), Duration.ofDays(30), java.util.Set.of(), Duration.ZERO));
+        server = new ImapServer(new ImapServer.Settings("127.0.0.1", 0, "mx.example.test", false,
+                SmtpTls.serverContext(null, null, tlsDir, "mx.example.test"), false, 1_000_000,
+                Duration.ofMinutes(5), Duration.ofMillis(200)), store, guard);
+        server.start();
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.tls("s");
+            assertThat(client.send("a LOGIN alice@example.test w1")).startsWith("a NO [AUTHENTICATIONFAILED]");
+            assertThat(client.send("b LOGIN alice@example.test w2")).startsWith("b NO [AUTHENTICATIONFAILED]");
+            assertThat(client.untilTagged("c", "c LOGIN alice@example.test w3")).contains("* BYE Too many failed logins");
+            assertThat(client.read()).isNull();
+        }
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.tls("s");
+            assertThat(client.send("a LOGIN alice@example.test w4")).startsWith("a NO [AUTHENTICATIONFAILED]");
+            assertThat(client.untilTagged("b", "b LOGIN alice@example.test secret"))
+                    .anyMatch(line -> line.startsWith("* BYE Too many failed logins, try again in 15 min"))
+                    .anyMatch(line -> line.startsWith("b NO [UNAVAILABLE]"));
+        }
+    }
+
+    @Test
+    void loginIsRefusedInPlainTextAndTheGreetingSaysSo() throws Exception {
+        try (Client client = new Client(server.port())) {
+            String greeting = client.read();
+            assertThat(greeting).contains("STARTTLS").contains("LOGINDISABLED").doesNotContain("AUTH=PLAIN");
+            assertThat(client.send("a LOGIN alice@example.test secret")).startsWith("a NO [PRIVACYREQUIRED]");
+        }
+    }
+
+    @Test
+    void literalsAndLiteralPlus() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.tls("s");
+            client.write("a LOGIN {18}\r\n");
+            assertThat(client.read()).startsWith("+ ");
+            client.write("alice@example.test {6+}\r\nsecret\r\n");
+            assertThat(client.read()).startsWith("a OK");
+            String message = "Subject: via literal+\r\n\r\nhi\r\n";
+            client.write("b APPEND Drafts (\\Seen) {" + message.length() + "+}\r\n" + message + "\r\n");
+            assertThat(client.read()).startsWith("b OK [APPENDUID");
+        }
+        assertThat(store.entries(store.box("Drafts").id())).hasSize(1);
+    }
+
+    @Test
+    void idleReportsNewMailUntilDone() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.tls("s");
+            client.send("a LOGIN alice@example.test secret");
+            client.untilTagged("b", "b SELECT INBOX");
+            client.write("c IDLE\r\n");
+            assertThat(client.read()).startsWith("+ idling");
+            store.deliver("INBOX", PLAIN);
+            assertThat(client.read()).isEqualTo("* 3 EXISTS");
+            client.write("DONE\r\n");
+            assertThat(client.read()).startsWith("c OK");
+            assertThat(client.send("d NOOP")).startsWith("d OK");
+        }
+    }
+
+    // CVE-2011-0411 class: commands sent in plain text right after STARTTLS must not run inside TLS
+    @Test
+    void plainTextAfterStartTlsIsNotExecuted() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.write("s STARTTLS\r\nx LOGIN alice@example.test secret\r\n");
+            assertThat(client.read()).startsWith("s OK");
+            String reply;
+            try {
+                client.startTls();
+                reply = client.read();
+            } catch (java.io.IOException closed) {
+                reply = null; // the server closed the connection — the expected outcome
+            }
+            assertThat(reply).isNull();
+        }
+    }
+
+    @Test
+    void sectionsOfANestedMessage() {
+        String raw = ("Subject: outer\r\nContent-Type: multipart/mixed; boundary=x\r\n\r\n"
+                + "--x\r\nContent-Type: text/plain\r\n\r\nouter text\r\n"
+                + "--x\r\nContent-Type: message/rfc822\r\n\r\nSubject: inner\r\nContent-Type: text/plain\r\n\r\ninner text\r\n"
+                + "--x--\r\n");
+        MimeTree tree = MimeTree.parse(raw.getBytes(StandardCharsets.US_ASCII));
+        assertThat(text(ImapSession.section(tree, "1"))).isEqualTo("outer text");
+        assertThat(text(ImapSession.section(tree, "2.HEADER"))).isEqualTo("Subject: inner\r\nContent-Type: text/plain\r\n\r\n");
+        assertThat(text(ImapSession.section(tree, "2.TEXT"))).isEqualTo("inner text");
+        assertThat(text(ImapSession.section(tree, "2.1"))).isEqualTo("inner text");
+        assertThat(text(ImapSession.section(tree, "1.MIME"))).isEqualTo("Content-Type: text/plain\r\n\r\n");
+        assertThat(text(ImapSession.section(tree, "HEADER.FIELDS (SUBJECT)"))).isEqualTo("Subject: outer\r\n\r\n");
+        assertThat(text(ImapSession.section(tree, ""))).isEqualTo(raw);
+    }
+
+    @Test
+    void mailboxNamesUseModifiedUtf7() {
+        // the example of RFC 3501 5.1.3
+        assertThat(ImapWriter.encodeMailbox("~peter/mail/台北/日本語")).isEqualTo("~peter/mail/&U,BTFw-/&ZeVnLIqe-");
+        assertThat(ImapWriter.decodeMailbox("~peter/mail/&U,BTFw-/&ZeVnLIqe-")).isEqualTo("~peter/mail/台北/日本語");
+        assertThat(ImapWriter.decodeMailbox(ImapWriter.encodeMailbox("Проекты & план"))).isEqualTo("Проекты & план");
+    }
+
+    private static String text(byte[] bytes) {
+        return new String(bytes, StandardCharsets.UTF_8);
+    }
+
+    /** Line-oriented IMAP test client. */
+    static final class Client implements AutoCloseable {
+        private Socket socket;
+        private BufferedReader in;
+        private OutputStream out;
+
+        Client(int port) throws Exception {
+            socket = new Socket("127.0.0.1", port);
+            socket.setSoTimeout(5000);
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8));
+            out = socket.getOutputStream();
+        }
+
+        void write(String text) throws Exception {
+            out.write(text.getBytes(StandardCharsets.UTF_8));
+            out.flush();
+        }
+
+        String read() throws Exception {
+            return in.readLine();
+        }
+
+        String send(String line) throws Exception {
+            write(line + "\r\n");
+            return read();
+        }
+
+        /** Sends a command, returns all lines up to its tagged response. */
+        List<String> untilTagged(String tag, String line) throws Exception {
+            write(line + "\r\n");
+            List<String> lines = new ArrayList<>();
+            String next;
+            do {
+                next = read();
+                lines.add(next);
+            } while (next != null && !next.startsWith(tag + " "));
+            return lines;
+        }
+
+        void tls(String tag) throws Exception {
+            assertThat(send(tag + " STARTTLS")).startsWith(tag + " OK");
+            startTls();
+        }
+
+        void startTls() throws Exception {
+            SSLContext context = SSLContext.getInstance("TLS");
+            context.init(null, new TrustManager[]{new X509TrustManager() {
+                public void checkClientTrusted(X509Certificate[] chain, String authType) {
+                }
+
+                public void checkServerTrusted(X509Certificate[] chain, String authType) {
+                }
+
+                public X509Certificate[] getAcceptedIssuers() {
+                    return new X509Certificate[0];
+                }
+            }}, null);
+            SSLSocket ssl = (SSLSocket) context.getSocketFactory().createSocket(socket, "127.0.0.1", socket.getPort(), true);
+            ssl.setUseClientMode(true);
+            ssl.startHandshake();
+            socket = ssl;
+            in = new BufferedReader(new InputStreamReader(ssl.getInputStream(), StandardCharsets.UTF_8));
+            out = ssl.getOutputStream();
+        }
+
+        @Override
+        public void close() throws Exception {
+            socket.close();
+        }
+    }
+}

backend/src/test/java/com/mailserver/imap/MemoryImapStore.java

@@ -0,0 +1,172 @@
+package com.mailserver.imap;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.atomic.AtomicLong;
+
+/** In-memory {@link ImapStore}: one user alice@example.test / secret with the system folders. */
+class MemoryImapStore implements ImapStore {
+
+    static final class Stored {
+        final long id;
+        volatile long folderId;
+        volatile long uid;
+        volatile boolean seen;
+        volatile boolean flagged;
+        volatile boolean answered;
+        volatile boolean deleted;
+        final Instant date;
+        final byte[] raw;
+
+        Stored(long id, long folderId, long uid, byte[] raw, Instant date) {
+            this.id = id;
+            this.folderId = folderId;
+            this.uid = uid;
+            this.raw = raw;
+            this.date = date;
+        }
+
+        Entry entry() {
+            return new Entry(id, uid, seen, flagged, answered, deleted, date);
+        }
+    }
+
+    private final AtomicLong ids = new AtomicLong(100);
+    final List<Mailbox> boxes = new CopyOnWriteArrayList<>();
+    final Map<Long, Long> uidNext = new ConcurrentHashMap<>();
+    final List<Stored> messages = new CopyOnWriteArrayList<>();
+
+    MemoryImapStore() {
+        for (String name : List.of("INBOX", "Drafts", "Sent", "Spam", "Trash")) {
+            addBox(name, true);
+        }
+    }
+
+    private Mailbox addBox(String name, boolean system) {
+        long id = ids.incrementAndGet();
+        uidNext.put(id, 1L);
+        Mailbox box = new Mailbox(id, name, system, 1700000000L + id, 1);
+        boxes.add(box);
+        return box;
+    }
+
+    Mailbox box(String name) {
+        return boxes.stream().filter(b -> b.name().equals(name)).findFirst().orElseThrow();
+    }
+
+    /** Delivers a message into a folder, as SMTP would. */
+    synchronized Stored deliver(String folder, String raw) {
+        Mailbox box = box(folder);
+        Stored stored = new Stored(ids.incrementAndGet(), box.id(), nextUid(box.id()),
+                raw.replace("\n", "\r\n").replace("\r\r\n", "\r\n").getBytes(), Instant.parse("2026-11-05T10:00:00Z"));
+        messages.add(stored);
+        return stored;
+    }
+
+    private synchronized long nextUid(long folderId) {
+        long uid = uidNext.get(folderId);
+        uidNext.put(folderId, uid + 1);
+        return uid;
+    }
+
+    @Override
+    public Account authenticate(String username, String password) {
+        return "alice@example.test".equalsIgnoreCase(username) && "secret".equals(password)
+                ? new Account(1, "alice@example.test") : null;
+    }
+
+    @Override
+    public List<Mailbox> mailboxes(long userId) {
+        return boxes.stream().map(b -> new Mailbox(b.id(), b.name(), b.system(), b.uidValidity(), uidNext.get(b.id()))).toList();
+    }
+
+    @Override
+    public synchronized Mailbox create(long userId, String name) {
+        return addBox(name, false);
+    }
+
+    @Override
+    public synchronized void rename(long userId, Mailbox mailbox, String newName) {
+        boxes.removeIf(b -> b.id() == mailbox.id());
+        boxes.add(new Mailbox(mailbox.id(), newName, false, mailbox.uidValidity(), mailbox.uidNext()));
+    }
+
+    @Override
+    public synchronized void delete(long userId, Mailbox mailbox) {
+        Mailbox trash = box("Trash");
+        move(userId, entries(mailbox.id()), trash);
+        boxes.removeIf(b -> b.id() == mailbox.id());
+    }
+
+    @Override
+    public List<Entry> entries(long folderId) {
+        return messages.stream().filter(m -> m.folderId == folderId)
+                .sorted((a, b) -> Long.compare(a.uid, b.uid)).map(Stored::entry).toList();
+    }
+
+    @Override
+    public byte[] source(long messageId) {
+        return find(messageId).raw;
+    }
+
+    private Stored find(long id) {
+        return messages.stream().filter(m -> m.id == id).findFirst().orElseThrow();
+    }
+
+    @Override
+    public void setFlags(long messageId, boolean seen, boolean flagged, boolean answered, boolean deleted) {
+        Stored m = find(messageId);
+        m.seen = seen;
+        m.flagged = flagged;
+        m.answered = answered;
+        m.deleted = deleted;
+    }
+
+    @Override
+    public synchronized long append(long userId, Mailbox target, byte[] raw, boolean seen, boolean flagged,
+                                    boolean answered, boolean deleted, Instant internalDate) {
+        Stored stored = new Stored(ids.incrementAndGet(), target.id(), nextUid(target.id()), raw,
+                internalDate == null ? Instant.now() : internalDate);
+        stored.seen = seen;
+        stored.flagged = flagged;
+        stored.answered = answered;
+        stored.deleted = deleted;
+        messages.add(stored);
+        return stored.uid;
+    }
+
+    @Override
+    public synchronized List<Long> copy(long userId, List<Entry> list, Mailbox target) {
+        List<Long> uids = new ArrayList<>();
+        for (Entry entry : list) {
+            Stored from = find(entry.id());
+            Stored copy = new Stored(ids.incrementAndGet(), target.id(), nextUid(target.id()), from.raw, from.date);
+            copy.seen = from.seen;
+            copy.flagged = from.flagged;
+            messages.add(copy);
+            uids.add(copy.uid);
+        }
+        return uids;
+    }
+
+    @Override
+    public synchronized List<Long> move(long userId, List<Entry> list, Mailbox target) {
+        List<Long> uids = new ArrayList<>();
+        for (Entry entry : list) {
+            Stored m = find(entry.id());
+            m.folderId = target.id();
+            m.uid = nextUid(target.id());
+            uids.add(m.uid);
+        }
+        return uids;
+    }
+
+    @Override
+    public void expunge(List<Long> messageIds) {
+        messages.removeIf(m -> messageIds.contains(m.id));
+    }
+}

backend/src/test/java/com/mailserver/security/LoginGuardTest.java

@@ -0,0 +1,164 @@
+package com.mailserver.security;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class LoginGuardTest {
+
+    /** Clock the test moves by hand. */
+    static final class TestClock extends Clock {
+        Instant now = Instant.parse("2026-11-06T12:00:00Z");
+
+        void plus(Duration d) {
+            now = now.plus(d);
+        }
+
+        @Override
+        public ZoneOffset getZone() {
+            return ZoneOffset.UTC;
+        }
+
+        @Override
+        public Clock withZone(java.time.ZoneId zone) {
+            return this;
+        }
+
+        @Override
+        public Instant instant() {
+            return now;
+        }
+    }
+
+    private final TestClock clock = new TestClock();
+
+    private LoginGuard guard(int perIp, int perAccount, String... trusted) {
+        return new LoginGuard(new LoginGuard.Settings(true, perIp, perAccount, Duration.ofMinutes(15),
+                Duration.ofMinutes(15), Duration.ofHours(24), Duration.ofDays(30), Set.of(trusted), Duration.ZERO), clock);
+    }
+
+    @Test
+    void ipIsBlockedAfterTheLimitWhateverMailboxItTries() {
+        LoginGuard guard = guard(3, 100);
+        for (int i = 0; i < 2; i++) {
+            guard.failure("1.2.3.4", "user" + i + "@x.test");
+        }
+        assertThat(guard.blocked("1.2.3.4", "any@x.test")).isFalse();
+        guard.failure("1.2.3.4", "user9@x.test");
+        assertThat(guard.retryAfter("1.2.3.4", "any@x.test")).isEqualTo(Duration.ofMinutes(15));
+        assertThat(guard.blocked("5.6.7.8", "any@x.test")).isFalse();
+
+        clock.plus(Duration.ofMinutes(15));
+        assertThat(guard.blocked("1.2.3.4", "any@x.test")).isFalse();
+    }
+
+    @Test
+    void failuresOutsideTheWindowDoNotCount() {
+        LoginGuard guard = guard(3, 100);
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        clock.plus(Duration.ofMinutes(16));
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.blocked("1.2.3.4", "a@x.test")).isFalse();
+    }
+
+    @Test
+    void eachNextBlockOfTheSameIpIsTwiceAsLongUpToTheMaximum() {
+        LoginGuard guard = guard(2, 100);
+        Duration expected = Duration.ofMinutes(15);
+        for (int round = 0; round < 10; round++) {
+            guard.failure("1.2.3.4", "a@x.test");
+            guard.failure("1.2.3.4", "a@x.test");
+            Duration wait = guard.retryAfter("1.2.3.4", "b@x.test");
+            assertThat(wait).isEqualTo(expected);
+            clock.plus(wait);
+            expected = expected.multipliedBy(2).compareTo(Duration.ofHours(24)) > 0 ? Duration.ofHours(24) : expected.multipliedBy(2);
+        }
+        // a quiet day forgives
+        clock.plus(Duration.ofHours(25));
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.retryAfter("1.2.3.4", "b@x.test")).isEqualTo(Duration.ofMinutes(15));
+    }
+
+    @Test
+    void attemptsWhileBlockedDoNotProlongTheBlock() {
+        LoginGuard guard = guard(2, 100);
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        clock.plus(Duration.ofMinutes(10));
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.retryAfter("1.2.3.4", "a@x.test")).isEqualTo(Duration.ofMinutes(5));
+    }
+
+    @Test
+    void distributedAttackBlocksTheMailboxButNotItsOwnerFromAKnownIp() {
+        LoginGuard guard = guard(100, 5);
+        guard.success("10.0.0.7", "Alice@X.test");
+        for (int i = 0; i < 5; i++) {
+            guard.failure("203.0.113." + i, "alice@x.test");
+        }
+        assertThat(guard.blocked("198.51.100.1", "alice@x.test")).isTrue();
+        assertThat(guard.blocked("198.51.100.1", "bob@x.test")).isFalse();
+        assertThat(guard.blocked("10.0.0.7", "alice@x.test")).isFalse();
+    }
+
+    @Test
+    void successForgivesTheIpFailuresButNotAnActiveBlock() {
+        LoginGuard guard = guard(3, 100);
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.success("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.blocked("1.2.3.4", "a@x.test")).isFalse();
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.blocked("1.2.3.4", "a@x.test")).isTrue();
+        guard.success("1.2.3.4", "a@x.test");
+        assertThat(guard.blocked("1.2.3.4", "other@x.test")).isTrue();
+    }
+
+    @Test
+    void trustedIpIsNeverBlockedByIp() {
+        LoginGuard guard = guard(2, 100, "172.18.0.1");
+        for (int i = 0; i < 10; i++) {
+            guard.failure("172.18.0.1", "u" + i + "@x.test");
+        }
+        assertThat(guard.blocked("172.18.0.1", "new@x.test")).isFalse();
+    }
+
+    @Test
+    void sweepForgetsOldKeys() {
+        LoginGuard guard = guard(5, 5);
+        guard.failure("1.2.3.4", "a@x.test");
+        assertThat(guard.trackedIps()).isEqualTo(1);
+        assertThat(guard.trackedAccounts()).isEqualTo(1);
+        clock.plus(Duration.ofHours(25).plusMinutes(16));
+        guard.sweep();
+        assertThat(guard.trackedIps()).isZero();
+        assertThat(guard.trackedAccounts()).isZero();
+    }
+
+    @Test
+    void disabledGuardNeverBlocks() {
+        LoginGuard guard = LoginGuard.disabled();
+        for (int i = 0; i < 100; i++) {
+            guard.failure("1.2.3.4", "a@x.test");
+        }
+        assertThat(guard.blocked("1.2.3.4", "a@x.test")).isFalse();
+        assertThat(guard.failureDelay()).isZero();
+    }
+
+    @Test
+    void humanDuration() {
+        assertThat(LoginGuard.human(Duration.ofSeconds(30))).isEqualTo("1 min");
+        assertThat(LoginGuard.human(Duration.ofMinutes(15))).isEqualTo("15 min");
+        assertThat(LoginGuard.human(Duration.ofHours(4))).isEqualTo("4 h");
+    }
+}

backend/src/test/java/com/mailserver/service/DkimServiceTest.java

@@ -0,0 +1,94 @@
+package com.mailserver.service;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.KeyPairGenerator;
+import java.security.interfaces.RSAPrivateKey;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class DkimServiceTest {
+
+    private static final String MESSAGE = "From: Alice <alice@ours.test>\r\nTo: bob@theirs.test\r\nSubject: Hello\r\n"
+            + "Date: Mon, 2 Nov 2026 10:00:00 +0000\r\nMessage-ID: <1@ours.test>\r\nMIME-Version: 1.0\r\n"
+            + "Content-Type: text/plain; charset=UTF-8\r\n\r\nHello Bob,\r\nsee you.\r\n";
+
+    @TempDir
+    Path keys;
+
+    /** Signer and a verifier that finds the signer's DNS record — like the receiving side would. */
+    private DkimService[] pair() {
+        DkimService signer = new DkimService("ours.test", "mail", keys, true, (method, selector, token) -> List.of());
+        signer.init();
+        DkimService verifier = new DkimService("other.test", "mail", keys.resolve("verifier"), false,
+                (method, selector, token) -> "mail".contentEquals(selector) && "ours.test".contentEquals(token)
+                        ? List.of(signer.dnsRecord()) : List.of());
+        return new DkimService[]{signer, verifier};
+    }
+
+    @Test
+    void signatureFromOurDomainVerifies() throws Exception {
+        DkimService[] p = pair();
+        byte[] signed = p[0].sign(MESSAGE.getBytes(StandardCharsets.UTF_8));
+
+        String text = new String(signed, StandardCharsets.UTF_8);
+        assertThat(text).startsWith("DKIM-Signature:").contains("c=relaxed/relaxed").contains("a=rsa-sha256")
+                .contains("d=ours.test").contains("s=mail");
+        DkimService.Verification result = p[1].verify(signed);
+        assertThat(result.signed()).isTrue();
+        assertThat(result.passed()).isTrue();
+        assertThat(result.domain()).isEqualTo("ours.test");
+    }
+
+    @Test
+    void changedBodyFailsVerification() throws Exception {
+        DkimService[] p = pair();
+        String signed = new String(p[0].sign(MESSAGE.getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8);
+        byte[] tampered = signed.replace("see you.", "send money.").getBytes(StandardCharsets.UTF_8);
+
+        DkimService.Verification result = p[1].verify(tampered);
+        assertThat(result.signed()).isTrue();
+        assertThat(result.passed()).isFalse();
+    }
+
+    @Test
+    void unsignedMessageIsReportedAsNone() {
+        DkimService.Verification result = pair()[1].verify(MESSAGE.getBytes(StandardCharsets.UTF_8));
+        assertThat(result.signed()).isFalse();
+    }
+
+    @Test
+    void mailFromAnotherDomainIsNotSigned() throws Exception {
+        byte[] foreign = MESSAGE.replace("alice@ours.test", "eve@elsewhere.test").getBytes(StandardCharsets.UTF_8);
+        assertThat(pair()[0].sign(foreign)).isEqualTo(foreign);
+    }
+
+    @Test
+    void keyIsKeptAcrossRestartsAndOldPkcs1FilesLoad() throws Exception {
+        DkimService first = new DkimService("ours.test", "mail", keys, true, (m, s, t) -> List.of());
+        first.init();
+        DkimService second = new DkimService("ours.test", "mail", keys, true, (m, s, t) -> List.of());
+        second.init();
+        assertThat(second.dnsRecord()).isEqualTo(first.dnsRecord()).startsWith("v=DKIM1; k=rsa; p=");
+
+        // the previous version wrote "BEGIN RSA PRIVATE KEY" (PKCS#1) and could not read it back
+        Path legacy = keys.resolve("legacy");
+        Files.createDirectories(legacy);
+        KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
+        generator.initialize(2048);
+        RSAPrivateKey key = (RSAPrivateKey) generator.generateKeyPair().getPrivate();
+        try (var writer = Files.newBufferedWriter(legacy.resolve("dkim-private.pem"));
+             var pem = new org.bouncycastle.openssl.jcajce.JcaPEMWriter(writer)) {
+            pem.writeObject(key);
+        }
+        assertThat(Files.readString(legacy.resolve("dkim-private.pem"))).contains("BEGIN RSA PRIVATE KEY");
+        DkimService loaded = new DkimService("ours.test", "mail", legacy, true, (m, s, t) -> List.of());
+        loaded.init();
+        assertThat(loaded.dnsRecord()).isNotNull();
+    }
+}

backend/src/test/java/com/mailserver/service/LocalDeliveryTest.java

@@ -0,0 +1,55 @@
+package com.mailserver.service;
+
+import jakarta.mail.Session;
+import jakarta.mail.internet.MimeMessage;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class LocalDeliveryTest {
+
+    private static MimeMessage parse(String text) throws Exception {
+        return new MimeMessage(Session.getInstance(new Properties()), new ByteArrayInputStream(text.getBytes(StandardCharsets.UTF_8)));
+    }
+
+    @Test
+    void prefersHtmlInNestedAlternativeAndSkipsAttachments() throws Exception {
+        MimeMessage message = parse("""
+                Content-Type: multipart/mixed; boundary="m"\r
+                \r
+                --m\r
+                Content-Type: multipart/alternative; boundary="a"\r
+                \r
+                --a\r
+                Content-Type: text/plain\r
+                \r
+                plain\r
+                --a\r
+                Content-Type: text/html\r
+                \r
+                <p>html</p>\r
+                --a--\r
+                --m\r
+                Content-Type: text/html\r
+                Content-Disposition: attachment; filename="x.html"\r
+                \r
+                <p>attached</p>\r
+                --m--\r
+                """);
+
+        LocalDelivery.Body body = LocalDelivery.body(message);
+        assertThat(body.html()).isTrue();
+        assertThat(body.text()).contains("<p>html</p>").doesNotContain("attached");
+    }
+
+    @Test
+    void plainTextMessage() throws Exception {
+        LocalDelivery.Body body = LocalDelivery.body(parse("Subject: x\r\n\r\njust text\r\n"));
+        assertThat(body.html()).isFalse();
+        assertThat(body.text()).isEqualTo("just text\r\n");
+    }
+}

backend/src/test/java/com/mailserver/service/SubmissionServiceTest.java

@@ -0,0 +1,84 @@
+package com.mailserver.service;
+
+import com.mailserver.domain.Attachment;
+import com.mailserver.domain.User;
+import com.mailserver.dto.SendRequest;
+import jakarta.mail.Message;
+import jakarta.mail.Session;
+import jakarta.mail.internet.MimeMessage;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class SubmissionServiceTest {
+
+    @Test
+    void addressesAreSplitLowercasedAndDeduplicated() {
+        assertThat(SubmissionService.addresses(" Bob@Mail.test, alice@mail.test;bob@mail.test  carol@x.org "))
+                .containsExactly("bob@mail.test", "alice@mail.test", "carol@x.org");
+        assertThat(SubmissionService.addresses(null)).isEmpty();
+        assertThat(SubmissionService.addresses("  ")).isEmpty();
+    }
+
+    @Test
+    void malformedAddressIsRejected() {
+        assertThatThrownBy(() -> SubmissionService.addresses("bob@mail.test, not-an-address"))
+                .isInstanceOf(ResponseStatusException.class)
+                .hasMessageContaining("not-an-address");
+    }
+
+    @Test
+    void attachmentsGoIntoTheMessageAndComeBackOutOnDelivery(@TempDir Path dir) throws Exception {
+        Path file = dir.resolve("report.pdf");
+        Files.writeString(file, "%PDF-1.4 test");
+        Attachment attachment = new Attachment();
+        attachment.setFilename("Отчёт 2026.pdf");
+        attachment.setContentType("application/pdf");
+        attachment.setFilePath(file.toString());
+
+        User user = new User();
+        user.setEmail("admin@mail.test");
+        user.setDisplayName("Admin");
+        SendRequest request = new SendRequest();
+        request.setSubject("Report");
+        request.setBody("See the file");
+
+        MimeMessage mime = SubmissionService.mime(user, List.of("bob@mail.test"), List.of("carol@mail.test"), request,
+                List.of(attachment));
+        ByteArrayOutputStream raw = new ByteArrayOutputStream();
+        mime.writeTo(raw);
+
+        MimeMessage parsed = new MimeMessage(Session.getInstance(new Properties()), new ByteArrayInputStream(raw.toByteArray()));
+        assertThat(parsed.getRecipients(Message.RecipientType.CC)[0].toString()).isEqualTo("carol@mail.test");
+        assertThat(LocalDelivery.addresses(parsed, Message.RecipientType.TO)).isEqualTo("bob@mail.test");
+        assertThat(LocalDelivery.addresses(parsed, Message.RecipientType.CC)).isEqualTo("carol@mail.test");
+        assertThat(LocalDelivery.body(parsed).text()).isEqualTo("See the file");
+        List<LocalDelivery.FilePart> files = LocalDelivery.attachments(parsed);
+        assertThat(files).hasSize(1);
+        assertThat(files.get(0).name()).isEqualTo("Отчёт 2026.pdf");
+        assertThat(files.get(0).contentType()).isEqualTo("application/pdf");
+        assertThat(new String(files.get(0).bytes(), StandardCharsets.UTF_8)).isEqualTo("%PDF-1.4 test");
+    }
+
+    @Test
+    void plainMessageHasNoAttachments() throws Exception {
+        User user = new User();
+        user.setEmail("admin@mail.test");
+        SendRequest request = new SendRequest();
+        request.setBody("Hi");
+        MimeMessage mime = SubmissionService.mime(user, List.of("bob@mail.test"), List.of(), request, List.of());
+        assertThat(LocalDelivery.attachments(mime)).isEmpty();
+        assertThat(LocalDelivery.body(mime).text()).isEqualTo("Hi");
+    }
+}

backend/src/test/java/com/mailserver/smtp/MailRouterTest.java

@@ -0,0 +1,68 @@
+package com.mailserver.smtp;
+
+import com.mailserver.config.MailDomains;
+import com.mailserver.delivery.OutboundQueue;
+import com.mailserver.delivery.SmtpDeliveryClient;
+import com.mailserver.repository.UserRepository;
+import com.mailserver.service.DkimService;
+import com.mailserver.service.LocalDelivery;
+import com.mailserver.service.UserService;
+import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/** Mail trap (75.4): existing mailboxes keep their mail, everything else goes into the catch-all mailbox. */
+class MailRouterTest {
+
+    private final UserRepository users = mock(UserRepository.class);
+    private final LocalDelivery localDelivery = mock(LocalDelivery.class);
+    private final OutboundQueue queue = mock(OutboundQueue.class);
+    private final SmtpDeliveryClient client = mock(SmtpDeliveryClient.class);
+
+    private MailRouter router(String catchAll) {
+        when(users.existsByEmail(anyString())).thenReturn(Mono.just(false));
+        when(users.existsByEmail("bob@mail.test")).thenReturn(Mono.just(true));
+        when(client.mode()).thenReturn(SmtpDeliveryClient.Mode.OFF);
+        return new MailRouter(new MailDomains("mail.test", catchAll), users, mock(UserService.class), localDelivery,
+                queue, mock(DkimService.class), client);
+    }
+
+    @Test
+    void withoutCatchAllUnknownAndOutsideAddressesAreRefused() {
+        MailRouter router = router("");
+
+        assertThat(router.route("bob@mail.test", null)).isEqualTo(SmtpBackend.Route.LOCAL);
+        assertThat(router.route("nobody@mail.test", null)).isEqualTo(SmtpBackend.Route.UNKNOWN_USER);
+        assertThat(router.route("user@gmail.com", null)).isEqualTo(SmtpBackend.Route.RELAY_DENIED);
+        assertThat(router.route("user@gmail.com", "bob@mail.test")).isEqualTo(SmtpBackend.Route.OUTBOUND_DISABLED);
+    }
+
+    @Test
+    void catchAllTakesEverythingWithoutItsOwnMailboxButExistingMailboxesKeepTheirMail() throws Exception {
+        MailRouter router = router("trap@mail.test");
+
+        assertThat(router.route("nobody@mail.test", null)).isEqualTo(SmtpBackend.Route.LOCAL);
+        assertThat(router.route("user@gmail.com", null)).isEqualTo(SmtpBackend.Route.LOCAL);
+        assertThat(router.mailbox("bob@mail.test")).isEqualTo("bob@mail.test");
+        assertThat(router.mailbox("user@gmail.com")).isEqualTo("trap@mail.test");
+
+        router.accept(new SmtpBackend.Envelope("10.0.0.5", "staging", "no-reply@jambotron.com", null, List.of(
+                new SmtpBackend.Recipient("user@gmail.com", SmtpBackend.Route.LOCAL),
+                new SmtpBackend.Recipient("bob@mail.test", SmtpBackend.Route.LOCAL))), "Subject: hi\r\n\r\nbody".getBytes());
+
+        verify(localDelivery).deliver(any(), eq("trap@mail.test"), eq("10.0.0.5"), eq("no-reply@jambotron.com"), anyBoolean());
+        verify(localDelivery).deliver(any(), eq("bob@mail.test"), eq("10.0.0.5"), eq("no-reply@jambotron.com"), anyBoolean());
+        verify(queue, never()).enqueue(any(), any(), any());
+    }
+}

backend/src/test/java/com/mailserver/smtp/ReloadingKeyManagerTest.java

@@ -0,0 +1,149 @@
+package com.mailserver.smtp;
+
+import org.bouncycastle.asn1.x500.X500Name;
+import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
+import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder;
+import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.StringWriter;
+import java.math.BigInteger;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.FileTime;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.cert.X509Certificate;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.Date;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ReloadingKeyManagerTest {
+
+    /** A clock moved by hand */
+    static final class TestClock extends Clock {
+        Instant now = Instant.parse("2026-11-06T12:00:00Z");
+
+        @Override
+        public ZoneOffset getZone() {
+            return ZoneOffset.UTC;
+        }
+
+        @Override
+        public Clock withZone(java.time.ZoneId zone) {
+            return this;
+        }
+
+        @Override
+        public Instant instant() {
+            return now;
+        }
+    }
+
+    @Test
+    void readsTheFilesAgainWhenTheyChange(@TempDir Path dir) throws Exception {
+        Path cert = dir.resolve("cert.pem");
+        Path key = dir.resolve("key.pem");
+        SmtpTls.selfSigned("old.example", cert, key);
+        TestClock clock = new TestClock();
+        ReloadingKeyManager manager = new ReloadingKeyManager(cert, key, Duration.ofMinutes(1), clock);
+
+        String first = manager.chooseEngineServerAlias("RSA", null, null);
+        assertEquals("CN=old.example", subject(manager.getCertificateChain(first)));
+        assertNull(manager.chooseEngineServerAlias("EC", null, null), "an RSA key is not offered for EC");
+
+        SmtpTls.selfSigned("new.example", cert, key);
+        Files.setLastModifiedTime(cert, FileTime.from(Instant.now().plusSeconds(5)));
+        Files.setLastModifiedTime(key, FileTime.from(Instant.now().plusSeconds(5)));
+
+        assertEquals(first, manager.chooseEngineServerAlias("RSA", null, null), "not checked before the interval");
+
+        clock.now = clock.now.plus(Duration.ofMinutes(1));
+        String second = manager.chooseEngineServerAlias("RSA", null, null);
+        assertNotEquals(first, second);
+        assertEquals("CN=new.example", subject(manager.getCertificateChain(second)));
+        assertNotNull(manager.getPrivateKey(second));
+        assertNotNull(manager.getCertificateChain(first), "a handshake that holds the previous alias still finishes");
+    }
+
+    @Test
+    void keepsTheOldCertificateWhenTheNewFileIsBroken(@TempDir Path dir) throws Exception {
+        Path cert = dir.resolve("cert.pem");
+        Path key = dir.resolve("key.pem");
+        SmtpTls.selfSigned("old.example", cert, key);
+        TestClock clock = new TestClock();
+        ReloadingKeyManager manager = new ReloadingKeyManager(cert, key, Duration.ofMinutes(1), clock);
+
+        Files.writeString(cert, "-----BEGIN CERTIFICATE-----\nhalf");
+        Files.setLastModifiedTime(cert, FileTime.from(Instant.now().plusSeconds(5)));
+        clock.now = clock.now.plus(Duration.ofMinutes(2));
+
+        String alias = manager.chooseEngineServerAlias("RSA", null, null);
+        assertEquals("CN=old.example", subject(manager.getCertificateChain(alias)));
+    }
+
+    @Test
+    void readsTraditionalEcKeysAsLegoWritesThem(@TempDir Path dir) throws Exception {
+        KeyPairGenerator generator = KeyPairGenerator.getInstance("EC");
+        generator.initialize(256);
+        KeyPair pair = generator.generateKeyPair();
+        X500Name name = new X500Name("CN=mail.example");
+        X509Certificate certificate = new JcaX509CertificateConverter().getCertificate(
+                new JcaX509v3CertificateBuilder(name, BigInteger.ONE, new Date(System.currentTimeMillis() - 86_400_000L),
+                        new Date(System.currentTimeMillis() + 86_400_000L), name, pair.getPublic())
+                        .build(new JcaContentSignerBuilder("SHA256withECDSA").build(pair.getPrivate())));
+        Path cert = dir.resolve("cert.pem");
+        Path key = dir.resolve("key.pem");
+        Files.writeString(cert, pem(certificate));
+        Files.writeString(key, sec1(pair)); // -----BEGIN EC PRIVATE KEY----- (SEC1 with the curve), not PKCS#8
+        assertTrue(Files.readString(key).contains("EC PRIVATE KEY"));
+
+        ReloadingKeyManager manager = new ReloadingKeyManager(cert, key, Duration.ofMinutes(1), new TestClock());
+        String alias = manager.chooseEngineServerAlias("EC", null, null);
+        assertNotNull(alias);
+        assertEquals("EC", manager.getPrivateKey(alias).getAlgorithm());
+        assertNull(manager.chooseEngineServerAlias("RSA", null, null));
+    }
+
+    @Test
+    void refusesAKeyThatDoesNotMatchTheCertificateType(@TempDir Path dir) throws Exception {
+        Path cert = dir.resolve("cert.pem");
+        Path key = dir.resolve("key.pem");
+        SmtpTls.selfSigned("rsa.example", cert, key);
+        KeyPairGenerator generator = KeyPairGenerator.getInstance("EC");
+        generator.initialize(256);
+        Files.writeString(key, sec1(generator.generateKeyPair()));
+        assertThrows(IllegalStateException.class,
+                () -> new ReloadingKeyManager(cert, key, Duration.ofMinutes(1), new TestClock()));
+    }
+
+    /** As lego and openssl ecparam -genkey write it: SEC1 with the named curve secp256r1 */
+    private static String sec1(KeyPair pair) throws Exception {
+        java.security.interfaces.ECPrivateKey key = (java.security.interfaces.ECPrivateKey) pair.getPrivate();
+        org.bouncycastle.asn1.sec.ECPrivateKey sec1 = new org.bouncycastle.asn1.sec.ECPrivateKey(256, key.getS(),
+                new org.bouncycastle.asn1.x9.X962Parameters(org.bouncycastle.asn1.sec.SECObjectIdentifiers.secp256r1));
+        StringWriter out = new StringWriter();
+        try (org.bouncycastle.util.io.pem.PemWriter writer = new org.bouncycastle.util.io.pem.PemWriter(out)) {
+            writer.writeObject(new org.bouncycastle.util.io.pem.PemObject("EC PRIVATE KEY", sec1.getEncoded()));
+        }
+        return out.toString();
+    }
+
+    private static String subject(X509Certificate[] chain) {
+        return chain[0].getSubjectX500Principal().getName();
+    }
+
+    private static String pem(Object object) throws Exception {
+        StringWriter out = new StringWriter();
+        try (JcaPEMWriter writer = new JcaPEMWriter(out)) {
+            writer.writeObject(object);
+        }
+        return out.toString();
+    }
+}

backend/src/test/java/com/mailserver/smtp/SmtpServerTest.java

@@ -0,0 +1,444 @@
+package com.mailserver.smtp;
+
+import jakarta.mail.Message;
+import jakarta.mail.Session;
+import jakarta.mail.Transport;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import com.mailserver.security.LoginGuard;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.Socket;
+import java.nio.file.Path;
+import java.security.cert.X509Certificate;
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocket;
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.X509TrustManager;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SmtpServerTest {
+
+    /** Mailboxes of example.test; alice can log in. */
+    static class FakeBackend implements SmtpBackend {
+        final Map<String, String> passwords = Map.of("alice@example.test", "secret");
+        final List<String> mailboxes = List.of("alice@example.test", "bob@example.test");
+        final List<Envelope> envelopes = new CopyOnWriteArrayList<>();
+        final List<String> messages = new CopyOnWriteArrayList<>();
+        volatile boolean failStore;
+
+        @Override
+        public boolean authenticate(String username, String password) {
+            return password.equals(passwords.get(username));
+        }
+
+        @Override
+        public Route route(String recipient, String authenticatedUser) {
+            if (recipient.endsWith("@example.test")) {
+                return mailboxes.contains(recipient) ? Route.LOCAL : Route.UNKNOWN_USER;
+            }
+            return authenticatedUser == null ? Route.RELAY_DENIED : Route.OUTBOUND;
+        }
+
+        @Override
+        public void accept(Envelope envelope, byte[] message) {
+            if (failStore) {
+                throw new IllegalStateException("database down");
+            }
+            envelopes.add(envelope);
+            messages.add(new String(message, StandardCharsets.UTF_8));
+        }
+    }
+
+    private FakeBackend backend;
+    private SmtpServer server;
+
+    @BeforeEach
+    void start() {
+        backend = new FakeBackend();
+        server = new SmtpServer(new SmtpServer.Settings("127.0.0.1", 0, "mx.example.test", 2000, true,
+                Duration.ofSeconds(30)), backend);
+        server.start();
+    }
+
+    @AfterEach
+    void stop() {
+        server.stop();
+    }
+
+    @Test
+    void storesMailFromARealClient() throws Exception {
+        Properties props = new Properties();
+        props.put("mail.smtp.host", "127.0.0.1");
+        props.put("mail.smtp.port", String.valueOf(server.port()));
+        Session session = Session.getInstance(props);
+        MimeMessage message = new MimeMessage(session);
+        message.setFrom(new InternetAddress("someone@elsewhere.test"));
+        message.setRecipient(Message.RecipientType.TO, new InternetAddress("bob@example.test"));
+        message.setSubject("Hello");
+        message.setText("first line\n.starts with a dot\nlast line");
+
+        Transport.send(message);
+
+        assertThat(backend.envelopes).hasSize(1);
+        SmtpBackend.Envelope envelope = backend.envelopes.get(0);
+        assertThat(envelope.mailFrom()).isEqualTo("someone@elsewhere.test");
+        assertThat(envelope.authenticatedUser()).isNull();
+        assertThat(envelope.recipients()).containsExactly(new SmtpBackend.Recipient("bob@example.test", SmtpBackend.Route.LOCAL));
+        assertThat(backend.messages.get(0))
+                .startsWith("Received: from ")
+                .contains("by mx.example.test with ESMTP;")
+                .contains("Subject: Hello")
+                .contains("\r\n.starts with a dot\r\n");
+    }
+
+    @Test
+    void handlesPipelinedCommandsInOnePacketAndLinesSplitAcrossPackets() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.write("EHLO c.test\r\nMAIL FROM:<x@elsewhere.test>\r\nRCPT TO:<bob@example.test>\r\nDATA\r\n");
+            assertThat(client.readReply()).startsWith("250-mx.example.test");
+            assertThat(client.read()).startsWith("250 2.1.0");
+            assertThat(client.read()).startsWith("250 2.1.5");
+            assertThat(client.read()).startsWith("354");
+            client.write("Subject: split\r\n\r\nhal");
+            client.write("f a line\r\n..dot\r\n.");
+            client.write("\r\nQUIT\r\n");
+            assertThat(client.read()).startsWith("250 2.0.0");
+            assertThat(client.read()).startsWith("221");
+        }
+        assertThat(backend.messages.get(0)).endsWith("Subject: split\r\n\r\nhalf a line\r\n.dot\r\n");
+    }
+
+    @Test
+    void refusesToRelayForStrangers() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO spammer.test");
+            client.readReply();
+            client.send("MAIL FROM:<spam@spammer.test>");
+            assertThat(client.send("RCPT TO:<victim@gmail.com>")).startsWith("550 5.7.1 Relaying denied");
+            assertThat(client.send("RCPT TO:<nobody@example.test>")).startsWith("550 5.1.1");
+            assertThat(client.send("DATA")).startsWith("554");
+        }
+        assertThat(backend.envelopes).isEmpty();
+    }
+
+    @Test
+    void relaysForALoggedInUserOnlyFromHisOwnAddress() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            assertThat(client.readReplyLines()).contains("250-AUTH PLAIN LOGIN");
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0wrong"))).startsWith("535");
+            assertThat(client.send("AUTH PLAIN " + b64("\0Alice@Example.test\0secret"))).startsWith("235");
+            assertThat(client.send("MAIL FROM:<bob@example.test>")).startsWith("553");
+            assertThat(client.send("MAIL FROM:<alice@example.test>")).startsWith("250");
+            assertThat(client.send("RCPT TO:<friend@gmail.com>")).startsWith("250");
+            assertThat(client.send("DATA")).startsWith("354");
+            assertThat(client.send("Subject: out\r\n\r\nhi\r\n.")).startsWith("250");
+        }
+        SmtpBackend.Envelope envelope = backend.envelopes.get(0);
+        assertThat(envelope.authenticatedUser()).isEqualTo("alice@example.test");
+        assertThat(envelope.recipients()).containsExactly(new SmtpBackend.Recipient("friend@gmail.com", SmtpBackend.Route.OUTBOUND));
+        assertThat(backend.messages.get(0)).contains("with ESMTPA;");
+    }
+
+    @Test
+    void threeWrongPasswordsCloseTheConnectionAndTheGuardBlocksTheIp() throws Exception {
+        server.stop();
+        LoginGuard guard = new LoginGuard(new LoginGuard.Settings(true, 4, 100, Duration.ofMinutes(15),
+                Duration.ofMinutes(15), Duration.ofHours(24), Duration.ofDays(30), java.util.Set.of(), Duration.ZERO));
+        server = new SmtpServer(new SmtpServer.Settings("127.0.0.1", 0, "mx.example.test", 2000, true,
+                Duration.ofSeconds(30)), backend, guard);
+        server.start();
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            client.readReplyLines();
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0w1"))).startsWith("535");
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0w2"))).startsWith("535");
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0w3"))).startsWith("535").contains("closing");
+            assertThat(client.read()).isNull();
+        }
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            client.readReplyLines();
+            assertThat(client.send("AUTH PLAIN " + b64("\0bob@example.test\0w4"))).startsWith("535");
+            // 4th failure from 127.0.0.1: blocked — even the right password is not checked
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0secret"))).startsWith("421 4.7.0");
+            assertThat(client.read()).isNull();
+        }
+    }
+
+    @Test
+    void authLoginWorksToo() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            client.readReply();
+            assertThat(client.send("AUTH LOGIN")).isEqualTo("334 " + b64("Username:"));
+            assertThat(client.send(b64("alice@example.test"))).isEqualTo("334 " + b64("Password:"));
+            assertThat(client.send(b64("secret"))).startsWith("235");
+        }
+    }
+
+    @Test
+    void rejectsTooBigMessagesAndKeepsTheSession() throws Exception {
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("HELO c");
+            client.send("MAIL FROM:<x@elsewhere.test>");
+            client.send("RCPT TO:<bob@example.test>");
+            client.send("DATA");
+            assertThat(client.send("x".repeat(3000) + "\r\n.")).startsWith("552");
+            assertThat(client.send("MAIL FROM:<x@elsewhere.test> SIZE=5000")).startsWith("552");
+            assertThat(client.send("NOOP")).startsWith("250");
+        }
+        assertThat(backend.envelopes).isEmpty();
+    }
+
+    @Test
+    void answers451WhenTheMessageCannotBeStored() throws Exception {
+        backend.failStore = true;
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("HELO c");
+            client.send("MAIL FROM:<x@elsewhere.test>");
+            client.send("RCPT TO:<bob@example.test>");
+            client.send("DATA");
+            assertThat(client.send("Subject: x\r\n\r\nbody\r\n.")).startsWith("451");
+        }
+    }
+
+    @Test
+    void withoutTlsAuthIsOffWhenNotAllowed() throws Exception {
+        server.stop();
+        server = new SmtpServer(new SmtpServer.Settings("127.0.0.1", 0, "mx.example.test", 2000, false,
+                Duration.ofSeconds(30)), backend);
+        server.start();
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            assertThat(client.readReplyLines()).noneMatch(line -> line.contains("AUTH"));
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0secret"))).startsWith("538");
+        }
+    }
+
+    @Test
+    void parsesPaths() {
+        assertThat(SmtpServer.path("<A@B.test> SIZE=10")).isEqualTo("a@b.test");
+        assertThat(SmtpServer.path("<>")).isEmpty();
+        assertThat(SmtpServer.path("<@relay.test:u@b.test>")).isEqualTo("u@b.test");
+        assertThat(SmtpServer.path("u@b.test")).isNull();
+        assertThat(SmtpServer.path("<a b@c>")).isNull();
+    }
+
+    // ---------- TLS (75.1) ----------
+
+    @TempDir
+    Path tlsDir;
+
+    private SmtpServer tlsServer(boolean implicit) throws Exception {
+        server.stop();
+        server = new SmtpServer(new SmtpServer.Settings("127.0.0.1", 0, "mx.example.test", 2000, false,
+                Duration.ofSeconds(30), SmtpTls.serverContext(null, null, tlsDir, "mx.example.test"), implicit), backend);
+        server.start();
+        return server;
+    }
+
+    @Test
+    void startTlsThenAuthAndTheSessionStartsOver() throws Exception {
+        tlsServer(false);
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            List<String> plain = client.readReplyLines();
+            assertThat(plain).contains("250-STARTTLS").noneMatch(line -> line.contains("AUTH"));
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0secret"))).startsWith("538");
+            assertThat(client.send("MAIL FROM:<x@elsewhere.test>")).startsWith("250");
+
+            assertThat(client.send("STARTTLS")).isEqualTo("220 2.0.0 Ready to start TLS");
+            client.startTls();
+
+            // RFC 3207: MAIL FROM before STARTTLS is forgotten, EHLO again
+            assertThat(client.send("MAIL FROM:<x@elsewhere.test>")).startsWith("503");
+            client.send("EHLO laptop");
+            List<String> secure = client.readReplyLines();
+            assertThat(secure).contains("250-AUTH PLAIN LOGIN").noneMatch(line -> line.contains("STARTTLS"));
+            assertThat(client.send("STARTTLS")).startsWith("503");
+            assertThat(client.send("AUTH PLAIN " + b64("\0alice@example.test\0secret"))).startsWith("235");
+            client.send("MAIL FROM:<alice@example.test>");
+            client.send("RCPT TO:<friend@gmail.com>");
+            client.send("DATA");
+            assertThat(client.send("Subject: tls\r\n\r\nhi\r\n.")).startsWith("250");
+        }
+        assertThat(backend.messages.get(0)).contains("with ESMTPSA;");
+    }
+
+    // CVE-2011-0411: commands sent in plain text right after STARTTLS must not run inside the TLS session
+    @Test
+    void plainTextInjectedAfterStartTlsIsNotExecuted() throws Exception {
+        tlsServer(false);
+        try (Client client = new Client(server.port())) {
+            client.read();
+            client.send("EHLO laptop");
+            client.readReplyLines();
+            client.write("STARTTLS\r\nMAIL FROM:<x@elsewhere.test>\r\nRCPT TO:<bob@example.test>\r\n");
+            assertThat(client.read()).isEqualTo("220 2.0.0 Ready to start TLS");
+            client.startTls();
+            String reply = client.read();
+            assertThat(reply == null || reply.startsWith("421")).as(reply).isTrue();
+        }
+        assertThat(backend.envelopes).isEmpty();
+    }
+
+    @Test
+    void realClientRequiringStartTlsDelivers() throws Exception {
+        tlsServer(false);
+        Properties props = new Properties();
+        props.put("mail.smtp.host", "127.0.0.1");
+        props.put("mail.smtp.port", String.valueOf(server.port()));
+        props.put("mail.smtp.starttls.enable", "true");
+        props.put("mail.smtp.starttls.required", "true");
+        props.put("mail.smtp.ssl.trust", "*");
+        props.put("mail.smtp.ssl.checkserveridentity", "false"); // self-signed for mx.example.test, connecting to 127.0.0.1
+        props.put("mail.smtp.auth", "true");
+        Session session = Session.getInstance(props);
+        MimeMessage message = new MimeMessage(session);
+        message.setFrom(new InternetAddress("alice@example.test"));
+        message.setRecipient(Message.RecipientType.TO, new InternetAddress("bob@example.test"));
+        message.setSubject("Over STARTTLS");
+        message.setText("hello");
+
+        Transport.send(message, "alice@example.test", "secret");
+
+        assertThat(backend.envelopes).hasSize(1);
+        assertThat(backend.envelopes.get(0).authenticatedUser()).isEqualTo("alice@example.test");
+        assertThat(backend.messages.get(0)).contains("with ESMTPSA;");
+    }
+
+    @Test
+    void implicitTlsPortWorksWithoutStartTls() throws Exception {
+        tlsServer(true);
+        Properties props = new Properties();
+        props.put("mail.smtp.host", "127.0.0.1");
+        props.put("mail.smtp.port", String.valueOf(server.port()));
+        props.put("mail.smtp.ssl.enable", "true");
+        props.put("mail.smtp.ssl.trust", "*");
+        props.put("mail.smtp.ssl.checkserveridentity", "false"); // self-signed for mx.example.test, connecting to 127.0.0.1
+        props.put("mail.smtp.auth", "true");
+        Session session = Session.getInstance(props);
+        MimeMessage message = new MimeMessage(session);
+        message.setFrom(new InternetAddress("alice@example.test"));
+        message.setRecipient(Message.RecipientType.TO, new InternetAddress("bob@example.test"));
+        message.setSubject("Over 465");
+        message.setText("hello");
+
+        Transport.send(message, "alice@example.test", "secret");
+
+        assertThat(backend.messages.get(0)).contains("with ESMTPSA;");
+    }
+
+    @Test
+    void selfSignedCertificateIsCreatedOnceAndReused() throws Exception {
+        SmtpTls.serverContext(null, null, tlsDir, "mx.example.test");
+        String first = java.nio.file.Files.readString(tlsDir.resolve(SmtpTls.CERT_FILE));
+        SmtpTls.serverContext(null, null, tlsDir, "mx.example.test");
+
+        assertThat(java.nio.file.Files.readString(tlsDir.resolve(SmtpTls.CERT_FILE))).isEqualTo(first);
+        assertThat(java.nio.file.Files.readString(tlsDir.resolve(SmtpTls.KEY_FILE))).startsWith("-----BEGIN PRIVATE KEY-----");
+    }
+
+    private static String b64(String text) {
+        return Base64.getEncoder().encodeToString(text.getBytes(StandardCharsets.UTF_8));
+    }
+
+    /** Line-oriented test client. */
+    static final class Client implements AutoCloseable {
+        private Socket socket;
+        private BufferedReader in;
+        private OutputStream out;
+
+        Client(int port) throws Exception {
+            socket = new Socket("127.0.0.1", port);
+            socket.setSoTimeout(5000);
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8));
+            out = socket.getOutputStream();
+        }
+
+        /** Upgrade the connection to TLS (any certificate is trusted — the test server's is self-signed). */
+        void startTls() throws Exception {
+            SSLContext context = SSLContext.getInstance("TLS");
+            context.init(null, new TrustManager[]{new X509TrustManager() {
+                public void checkClientTrusted(X509Certificate[] chain, String authType) {
+                }
+
+                public void checkServerTrusted(X509Certificate[] chain, String authType) {
+                }
+
+                public X509Certificate[] getAcceptedIssuers() {
+                    return new X509Certificate[0];
+                }
+            }}, null);
+            SSLSocket ssl = (SSLSocket) context.getSocketFactory().createSocket(socket, "127.0.0.1", socket.getPort(), true);
+            ssl.setUseClientMode(true);
+            ssl.startHandshake();
+            socket = ssl;
+            in = new BufferedReader(new InputStreamReader(ssl.getInputStream(), StandardCharsets.UTF_8));
+            out = ssl.getOutputStream();
+        }
+
+        void write(String text) throws Exception {
+            out.write(text.getBytes(StandardCharsets.UTF_8));
+            out.flush();
+            Thread.sleep(50); // separate TCP packets
+        }
+
+        String send(String line) throws Exception {
+            out.write((line + "\r\n").getBytes(StandardCharsets.UTF_8));
+            out.flush();
+            return read();
+        }
+
+        String read() throws Exception {
+            return in.readLine();
+        }
+
+        /** First line of a multi-line reply; the rest is consumed. */
+        String readReply() throws Exception {
+            return readReplyLines().get(0);
+        }
+
+        List<String> readReplyLines() throws Exception {
+            List<String> lines = new ArrayList<>();
+            String line;
+            do {
+                line = in.readLine();
+                lines.add(line);
+            } while (line != null && line.length() > 3 && line.charAt(3) == '-');
+            return lines;
+        }
+
+        @Override
+        public void close() throws Exception {
+            socket.close();
+        }
+    }
+}

docker-compose.image.yml

@@ -0,0 +1,84 @@
+# Same stand as docker-compose.jambotron.yml, but from the ready image — nothing is built on the VM:
+# gitea.jambotron.com/jambotron_gang/reactive-mail-server (Drone builds it from master, see .drone.yml).
+# Pin a build: MAIL_IMAGE_TAG=<first 8 chars of the master commit>; default latest (pulled again on every deploy).
+# Test deploy on Jambotron (v0.2.3 75.3): pick this file in the deploy wizard.
+# Outside, only the web client + API (service "mail", port 8080) through Jambotron's Caddy — give it a domain.
+# SMTP (3025) stays inside the VM's docker network; nothing is sent outside (OUTBOUND_MODE=off).
+# Secrets are generated on the first start into the "secrets" volume — nothing to type in, nothing in git.
+# Mailboxes admin@<MAIL_DOMAINS> and trap@mail.test (catch-all): passwords in the "mail" log on the first start
+# (Jambotron: project → Services → mail → Logs) and in /app/data/initial-passwords.txt
+# of the "mail" container (docker exec <mail container> cat /app/data/initial-passwords.txt).
+name: reactive-mail
+
+services:
+  secrets-init:
+    image: alpine:3.20
+    restart: "no"
+    command:
+      - sh
+      - -c
+      - |
+        umask 077
+        for name in DB_PASSWORD JWT_SECRET; do
+          [ -s /secrets/$$name ] || head -c 48 /dev/urandom | base64 | tr -dc 'A-Za-z0-9' > /secrets/$$name
+        done
+        # postgres reads it as uid 70, the app as uid 10001 — readable inside these containers only
+        chmod 644 /secrets/DB_PASSWORD /secrets/JWT_SECRET
+    volumes:
+      - secrets:/secrets
+
+  db:
+    # Debian, not -alpine: on Jambotron staging VMs (Alpine 3.24, kernel 6.18) the Alpine build of postgres
+    # dies with "Bus error" even on --version; the Debian build works (2026-11-05)
+    image: postgres:17
+    restart: unless-stopped
+    depends_on:
+      secrets-init:
+        condition: service_completed_successfully
+    environment:
+      POSTGRES_DB: mailserver
+      POSTGRES_USER: mail
+      POSTGRES_PASSWORD_FILE: /run/mail-secrets/DB_PASSWORD
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+      - secrets:/run/mail-secrets:ro
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U mail -d mailserver"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+    mem_limit: 256m
+
+  mail:
+    image: gitea.jambotron.com/jambotron_gang/reactive-mail-server:${MAIL_IMAGE_TAG:-latest}
+    pull_policy: always
+    restart: unless-stopped
+    depends_on:
+      db:
+        condition: service_healthy
+    expose:
+      - "8080"   # web client + API → domain in Jambotron
+      - "3025"   # SMTP, inside the network only
+      - "3143"   # IMAP (STARTTLS), inside the network only — open it in Jambotron as an internal TCP port
+    environment:
+      DB_HOST: db
+      MAILSERVER_SECRETS_DIR: /run/mail-secrets
+      MAIL_DOMAINS: ${MAIL_DOMAINS:-mail.test}
+      MAIL_HOSTNAME: ${MAIL_HOSTNAME:-mail.test}
+      DKIM_DOMAIN: ${MAIL_DOMAINS:-mail.test}
+      # mail trap: mail to any address without its own mailbox here (also gmail.com etc.) goes into this mailbox
+      MAIL_CATCH_ALL: ${MAIL_CATCH_ALL:-trap@mail.test}
+      MAIL_REGISTRATION: ${MAIL_REGISTRATION:-true}   # test stand: anyone can create a mailbox in MAIL_DOMAINS (nothing goes outside)
+      OUTBOUND_MODE: "off"
+      SMTP_AUTH_WITHOUT_TLS: "true"   # SMTP is not reachable from outside the VM
+      SPF_ENABLED: "false"
+      DMARC_ENABLED: "false"
+    volumes:
+      - data:/app/data
+      - secrets:/run/mail-secrets:ro
+    mem_limit: 512m
+
+volumes:
+  secrets:
+  pgdata:
+  data:

docker-compose.jambotron.yml

@@ -0,0 +1,82 @@
+# Test deploy on Jambotron (v0.2.3 75.3): pick this file in the deploy wizard.
+# Outside, only the web client + API (service "mail", port 8080) through Jambotron's Caddy — give it a domain.
+# SMTP (3025) stays inside the VM's docker network; nothing is sent outside (OUTBOUND_MODE=off).
+# Secrets are generated on the first start into the "secrets" volume — nothing to type in, nothing in git.
+# Mailboxes admin@<MAIL_DOMAINS> and trap@mail.test (catch-all): passwords in the "mail" log on the first start
+# (Jambotron: project → Services → mail → Logs) and in /app/data/initial-passwords.txt
+# of the "mail" container (docker exec <mail container> cat /app/data/initial-passwords.txt).
+name: reactive-mail
+
+services:
+  secrets-init:
+    image: alpine:3.20
+    restart: "no"
+    command:
+      - sh
+      - -c
+      - |
+        umask 077
+        for name in DB_PASSWORD JWT_SECRET; do
+          [ -s /secrets/$$name ] || head -c 48 /dev/urandom | base64 | tr -dc 'A-Za-z0-9' > /secrets/$$name
+        done
+        # postgres reads it as uid 70, the app as uid 10001 — readable inside these containers only
+        chmod 644 /secrets/DB_PASSWORD /secrets/JWT_SECRET
+    volumes:
+      - secrets:/secrets
+
+  db:
+    # Debian, not -alpine: on Jambotron staging VMs (Alpine 3.24, kernel 6.18) the Alpine build of postgres
+    # dies with "Bus error" even on --version; the Debian build works (2026-11-05)
+    image: postgres:17
+    restart: unless-stopped
+    depends_on:
+      secrets-init:
+        condition: service_completed_successfully
+    environment:
+      POSTGRES_DB: mailserver
+      POSTGRES_USER: mail
+      POSTGRES_PASSWORD_FILE: /run/mail-secrets/DB_PASSWORD
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+      - secrets:/run/mail-secrets:ro
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U mail -d mailserver"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+    mem_limit: 256m
+
+  mail:
+    build:
+      context: .
+      dockerfile: backend/Dockerfile
+    restart: unless-stopped
+    depends_on:
+      db:
+        condition: service_healthy
+    expose:
+      - "8080"   # web client + API → domain in Jambotron
+      - "3025"   # SMTP, inside the network only
+      - "3143"   # IMAP (STARTTLS), inside the network only — open it in Jambotron as an internal TCP port
+    environment:
+      DB_HOST: db
+      MAILSERVER_SECRETS_DIR: /run/mail-secrets
+      MAIL_DOMAINS: ${MAIL_DOMAINS:-mail.test}
+      MAIL_HOSTNAME: ${MAIL_HOSTNAME:-mail.test}
+      DKIM_DOMAIN: ${MAIL_DOMAINS:-mail.test}
+      # mail trap: mail to any address without its own mailbox here (also gmail.com etc.) goes into this mailbox
+      MAIL_CATCH_ALL: ${MAIL_CATCH_ALL:-trap@mail.test}
+      MAIL_REGISTRATION: ${MAIL_REGISTRATION:-true}   # test stand: anyone can create a mailbox in MAIL_DOMAINS (nothing goes outside)
+      OUTBOUND_MODE: "off"
+      SMTP_AUTH_WITHOUT_TLS: "true"   # SMTP is not reachable from outside the VM
+      SPF_ENABLED: "false"
+      DMARC_ENABLED: "false"
+    volumes:
+      - data:/app/data
+      - secrets:/run/mail-secrets:ro
+    mem_limit: 512m
+
+volumes:
+  secrets:
+  pgdata:
+  data:

docker-compose.prod.yml

@@ -1,91 +0,0 @@
-services:
-  # PostgreSQL — база данных
-  postgres:
-    image: postgres:16-alpine
-    container_name: mail-postgres
-    restart: unless-stopped
-    environment:
-      POSTGRES_DB: mailserver
-      POSTGRES_USER: mail
-      POSTGRES_PASSWORD: secret
-    ports:
-      - "5432:5432"
-    volumes:
-      - pgdata:/var/lib/postgresql/data
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U mail"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-
-  # Почтовый сервер (Spring Boot WebFlux)
-  mail-server:
-    build:
-      context: ./backend
-      dockerfile: Dockerfile
-    container_name: mail-server
-    restart: unless-stopped
-    depends_on:
-      postgres:
-        condition: service_healthy
-    environment:
-      SPRING_PROFILES_ACTIVE: prod
-      SPRING_R2DBC_URL: r2dbc:postgresql://postgres:5432/mailserver
-      SPRING_R2DBC_USERNAME: mail
-      SPRING_R2DBC_PASSWORD: secret
-      SPRING_FLYWAY_URL: jdbc:postgresql://postgres:5432/mailserver
-      SPRING_FLYWAY_USER: mail
-      SPRING_FLYWAY_PASSWORD: secret
-      MAILSERVER_SMTP_HOSTNAME: mail.jambotron.com
-      MAILSERVER_SMTP_PORT: 3025
-      MAILSERVER_RELAY_ENABLED: "true"
-      MAILSERVER_RELAY_PORT: 25
-      MAILSERVER_DKIM_DOMAIN: jambotron.com
-    ports:
-      - "3025:3025"   # SMTP входящие (не через Caddy)
-    volumes:
-      - attachments:/app/attachments
-      - dkim-keys:/app/dkim-keys
-      - ./frontend/dist/frontend/browser:/usr/share/caddy  # Статический фронтенд
-    healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost:8080/actuator/health"]
-      interval: 30s
-      timeout: 5s
-      retries: 3
-    labels:
-      # Caddy Docker Proxy — автоматический HTTPS + reverse proxy
-      caddy: mail.jambotron.com
-      caddy.route.api.reverse_proxy: "*{{upstreams 8080}}"
-      caddy.route.api.header_up.Host: "{host}"
-      caddy.route.api.header_up.X-Real-IP: "{remote_host}"
-      caddy.route.api.header_up.X-Forwarded-For: "{remote_host}"
-      caddy.route.api.header_up.X-Forwarded-Proto: "{scheme}"
-      # Статический фронтенд (Angular) — file_server для всех остальных путей
-      caddy.route.static.root: "* /usr/share/caddy"
-      caddy.route.static.file_server: "*"
-      caddy.route.static.encode: "gzip"
-
-  # Caddy Docker Proxy — автоматически генерирует Caddyfile из labels
-  caddy:
-    image: lucaslorentz/caddy-docker-proxy:2.8-alpine
-    container_name: mail-caddy
-    restart: unless-stopped
-    ports:
-      - "80:80"
-      - "443:443"
-      - "443:443/udp"  # ACME DNS-01 challenge
-    volumes:
-      - /var/run/docker.sock:/var/run/docker.sock:ro
-      - caddy-data:/data
-      - caddy-config:/config
-    environment:
-      CADDY_DOCKER_CADDYFILE: ""
-      CADDY_DOCKER_AGREE: "true"
-      CADDY_DOCKER_TLS_DEFAULT_ROUTE: "true"
-
-volumes:
-  pgdata:
-  attachments:
-  dkim-keys:
-  caddy-data:
-  caddy-config:

docker-compose.public.yml

@@ -0,0 +1,159 @@
+# Real mail on the internet (v0.2.3 75.6): receives mail for MAIL_DOMAINS and sends it straight to the recipients'
+# MX servers (port 25), DKIM-signed. From the ready image, like docker-compose.image.yml.
+#
+# Needs a VM of its own with a public address (Jambotron 60.8: «Публичный адрес» of the VM, SMTP «да» — port 25
+# is closed by default) — the ports below are published on that address:
+#   25   SMTP: mail from other servers (STARTTLS) and from mail programs
+#   587  submission: mail programs (STARTTLS + login) — the same SMTP listener as 25
+#   465  SMTPS: mail programs, implicit TLS
+#   993  IMAPS: mail programs, implicit TLS
+#   80   only for Let's Encrypt (HTTP-01) — service "acme"
+#   443  web client + API over HTTPS, same Let's Encrypt certificate (acme): https://mail.jambocheck.com
+# The web client + API can also go through Jambotron's Caddy (plain port 8080) under ANOTHER name
+# (webmail.<domain>): the name MAIL_HOSTNAME points at the VM's public address, not at Caddy.
+#
+# DNS before the first start (the certificate is issued over HTTP on MAIL_HOSTNAME):
+#   A    mail.<domain>             → public address of the VM
+#   PTR  public address            → mail.<domain>        (hoster's panel: Reverse DNS)
+#   MX   <domain>                  → 10 mail.<domain>
+#   TXT  <domain>                  → "v=spf1 ip4:<public address> -all"
+#   TXT  _dmarc.<domain>           → "v=DMARC1; p=none; rua=mailto:postmaster@<domain>"
+#   TXT  mail._domainkey.<domain>  → printed in the "mail" log on the first start (DKIM key, kept in the data volume)
+#
+# Mailbox admin@<domain>: its password is in the "mail" log on the first start and in /app/data/initial-passwords.txt.
+# Registration is closed: new mailboxes only by the admin. No catch-all.
+# Defaults are ours (mail.jambocheck.com / jambocheck.com) — Jambotron deploys without a .env; another domain:
+# MAIL_HOSTNAME, MAIL_DOMAINS, ACME_EMAIL in .env next to this file.
+name: reactive-mail-public
+
+services:
+  secrets-init:
+    image: alpine:3.20
+    restart: "no"
+    command:
+      - sh
+      - -c
+      - |
+        umask 077
+        for name in DB_PASSWORD JWT_SECRET; do
+          [ -s /secrets/$$name ] || head -c 48 /dev/urandom | base64 | tr -dc 'A-Za-z0-9' > /secrets/$$name
+        done
+        chmod 644 /secrets/DB_PASSWORD /secrets/JWT_SECRET
+    volumes:
+      - secrets:/secrets
+
+  # Let's Encrypt for MAIL_HOSTNAME: issued on the first start, renewed 30 days before the end (checked twice a day).
+  # The deploy hook copies the pair to /tls (readable by the "mail" user 10001); the server reads it again within
+  # a minute — no restart
+  acme:
+    image: goacme/lego:v5.5.2
+    restart: unless-stopped
+    ports:
+      - "80:80"
+    entrypoint:
+      - sh
+      - -c
+      - |
+        cat > /usr/local/bin/jb-deploy <<'EOF'
+        #!/bin/sh
+        set -e
+        cp "$$LEGO_HOOK_CERT_PATH" /tls/cert.pem.new
+        cp "$$LEGO_HOOK_CERT_KEY_PATH" /tls/key.pem.new
+        chown 10001 /tls/cert.pem.new /tls/key.pem.new
+        chmod 600 /tls/key.pem.new
+        chmod 644 /tls/cert.pem.new
+        mv /tls/key.pem.new /tls/key.pem
+        mv /tls/cert.pem.new /tls/cert.pem
+        echo "certificate for $$LEGO_HOOK_CERT_DOMAINS copied to /tls"
+        EOF
+        chmod 755 /usr/local/bin/jb-deploy
+        while true; do
+          /lego run --accept-tos --email "$$ACME_EMAIL" --domains "$$MAIL_HOSTNAME" --key-type EC256 \
+            --http --http.address :80 --path /var/lib/lego --renew-days 30 --no-random-sleep \
+            --deploy-hook /usr/local/bin/jb-deploy || echo "lego failed — next try in 1 hour"
+          [ -s /tls/cert.pem ] && sleep 43200 || sleep 3600
+        done
+    environment:
+      MAIL_HOSTNAME: ${MAIL_HOSTNAME:-mail.jambocheck.com}
+      ACME_EMAIL: ${ACME_EMAIL:-postmaster@jambocheck.com}
+      LEGO_LOG_FORMAT: text
+    volumes:
+      - lego:/var/lib/lego
+      - tls:/tls
+    healthcheck:
+      test: ["CMD-SHELL", "test -s /tls/cert.pem && test -s /tls/key.pem"]
+      interval: 15s
+      timeout: 5s
+      start_period: 10m
+      retries: 3
+    mem_limit: 128m
+
+  db:
+    image: postgres:17
+    restart: unless-stopped
+    depends_on:
+      secrets-init:
+        condition: service_completed_successfully
+    environment:
+      POSTGRES_DB: mailserver
+      POSTGRES_USER: mail
+      POSTGRES_PASSWORD_FILE: /run/mail-secrets/DB_PASSWORD
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+      - secrets:/run/mail-secrets:ro
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U mail -d mailserver"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+    mem_limit: 256m
+
+  mail:
+    image: gitea.jambotron.com/jambotron_gang/reactive-mail-server:${MAIL_IMAGE_TAG:-latest}
+    pull_policy: always
+    restart: unless-stopped
+    depends_on:
+      db:
+        condition: service_healthy
+      acme:
+        condition: service_healthy   # waits for the first certificate
+    ports:
+      - "25:3025"
+      - "587:3025"
+      - "465:3465"
+      - "993:3993"
+      - "443:8443"   # web client + API over HTTPS: https://mail.jambocheck.com
+    expose:
+      - "8080"   # plain HTTP, for a reverse proxy inside the network (not needed on the public address)
+    environment:
+      DB_HOST: db
+      MAILSERVER_SECRETS_DIR: /run/mail-secrets
+      MAIL_DOMAINS: ${MAIL_DOMAINS:-jambocheck.com}
+      MAIL_HOSTNAME: ${MAIL_HOSTNAME:-mail.jambocheck.com}
+      MAIL_TLS_CERT: /tls/cert.pem
+      MAIL_TLS_KEY: /tls/key.pem
+      SMTPS_PORT: "3465"
+      IMAPS_PORT: "3993"
+      HTTPS_PORT: "8443"
+      DKIM_DOMAIN: ${MAIL_DOMAINS:-jambocheck.com}
+      DKIM_SELECTOR: mail
+      DKIM_KEYS_DIR: /app/data/dkim-keys
+      MAIL_CATCH_ALL: ""
+      MAIL_REGISTRATION: "false"
+      OUTBOUND_MODE: mx
+      SMTP_AUTH_WITHOUT_TLS: "false"
+      IMAP_AUTH_WITHOUT_TLS: "false"
+      SPF_ENABLED: "true"
+      DMARC_ENABLED: "true"
+    volumes:
+      - data:/app/data
+      - secrets:/run/mail-secrets:ro
+      - tls:/tls:ro
+    mem_limit: 512m
+
+volumes:
+  secrets:
+  pgdata:
+  data:
+  lego:
+  tls:

docker-compose.yml

@@ -1,32 +1,8 @@
-version: '3.8'
+# Local development: Postgres on localhost:5433 for `./gradlew :backend:bootRun --args='--spring.profiles.active=dev'`
-
+# and `cd frontend && npx ng serve` (proxy /api → :8080). Passwords here are for this laptop only.
 services:
-  mail-server:
-    build:
-      context: .
-      dockerfile: ./backend/Dockerfile
-    ports:
-      - "8080:8080"    # REST API
-      - "3026:3025" # SMTP (приём писем)
-      - "1443:143"   # IMAP (доступ к письмам)
-    volumes:
-      - attachments:/app/attachments
-      - dkim-keys:/app/dkim-keys
-    environment:
-      - SPRING_R2DBC_URL=r2dbc:postgresql://db:5432/mailserver
-      - SPRING_R2DBC_USERNAME=mail
-      - SPRING_R2DBC_PASSWORD=secret
-      - SPRING_FLYWAY_URL=jdbc:postgresql://db:5432/mailserver
-      - SPRING_FLYWAY_USER=mail
-      - SPRING_FLYWAY_PASSWORD=secret
-      - SPRING_MAIL_HOST=mailpit
-      - SPRING_MAIL_PORT=1025
-    depends_on:
-      - db
-      - mailpit
-
   db:
-    image: postgres:17
+    image: postgres:17-alpine
     environment:
       POSTGRES_DB: mailserver
       POSTGRES_USER: mail
@@ -34,18 +10,7 @@ services:
     volumes:
       - pg-data:/var/lib/postgresql/data
     ports:
-      - "5433:5432"
+      - "127.0.0.1:5433:5432"
-
-  mailpit:
-    image: axllent/mailpit
-    ports:
-      - "1025:1025"  # SMTP
-      - "8025:8025"  # Web UI
-    volumes:
-      - mailpit-data:/data
 
 volumes:
-  attachments:
   pg-data:
-  mailpit-data:
-  dkim-keys:

frontend/.npmrc

@@ -0,0 +1 @@
+@jambotron:registry=https://gitea.jambotron.com/api/packages/jambotron_gang/npm/

frontend/angular.json

@@ -50,6 +50,7 @@
               }
             ],
             "styles": [
+              "src/material.scss",
               "src/styles.css"
             ]
           },
@@ -58,13 +59,13 @@
               "budgets": [
                 {
                   "type": "initial",
-                  "maximumWarning": "500kB",
+                  "maximumWarning": "1MB",
-                  "maximumError": "1MB"
+                  "maximumError": "2MB"
                 },
                 {
                   "type": "anyComponentStyle",
-                  "maximumWarning": "4kB",
+                  "maximumWarning": "8kB",
-                  "maximumError": "8kB"
+                  "maximumError": "16kB"
                 }
               ],
               "outputHashing": "all"
@@ -87,7 +88,10 @@
               "buildTarget": "frontend:build:development"
             }
           },
-          "defaultConfiguration": "development"
+          "defaultConfiguration": "development",
+          "options": {
+            "proxyConfig": "proxy.conf.json"
+          }
         }
       }
     }

frontend/package.json

@@ -11,12 +11,16 @@
   "private": true,
   "packageManager": "npm@11.17.0",
   "dependencies": {
+    "@angular/aria": "^22.2.6",
+    "@angular/cdk": "^22.2.6",
     "@angular/common": "^22.2.0",
     "@angular/compiler": "^22.2.0",
     "@angular/core": "^22.2.0",
     "@angular/forms": "^22.2.0",
+    "@angular/material": "^22.2.6",
     "@angular/platform-browser": "^22.2.0",
     "@angular/router": "^22.2.0",
+    "@jambotron/aria-grid": "0.1.0",
     "rxjs": "~7.8.0",
     "tslib": "^2.3.0"
   },

frontend/proxy.conf.json

@@ -0,0 +1,6 @@
+{
+  "/api": {
+    "target": "http://localhost:8080",
+    "secure": false
+  }
+}

frontend/src/app/app.config.ts

@@ -1,13 +1,15 @@
 import { ApplicationConfig, provideBrowserGlobalErrorListeners } from '@angular/core';
-import { provideRouter, withHashLocation } from '@angular/router';
+import { provideRouter, withComponentInputBinding } from '@angular/router';
 import { provideHttpClient, withInterceptors } from '@angular/common/http';
 import { routes } from './app.routes';
-import { authInterceptor } from './interceptors/auth.interceptor';
+import { authInterceptor } from './core/auth';
+import { provideMailGrid } from './ui/grid';
 
 export const appConfig: ApplicationConfig = {
   providers: [
     provideBrowserGlobalErrorListeners(),
-    provideRouter(routes),
+    provideRouter(routes, withComponentInputBinding()),
-    provideHttpClient(withInterceptors([authInterceptor]))
+    provideHttpClient(withInterceptors([authInterceptor])),
+    provideMailGrid()
   ]
 };

frontend/src/app/app.routes.ts

@@ -1,43 +1,23 @@
 import { Routes } from '@angular/router';
+import { authGuard, guestGuard } from './core/auth';
 
 export const routes: Routes = [
-  {
+  { path: 'login', canActivate: [guestGuard], loadComponent: () => import('./pages/auth/login.page').then(m => m.LoginPage) },
-    path: 'login',
+  { path: 'register', canActivate: [guestGuard], loadComponent: () => import('./pages/auth/register.page').then(m => m.RegisterPage) },
-    loadComponent: () => import('./components/login/login.component'),
-  },
-  {
-    path: 'register',
-    loadComponent: () => import('./components/register/register.component'),
-  },
   {
     path: '',
-    loadComponent: () => import('./components/layout/layout.component'),
+    canActivate: [authGuard],
+    loadComponent: () => import('./pages/shell/shell.component').then(m => m.ShellComponent),
     children: [
-      {
+      { path: '', pathMatch: 'full', loadComponent: () => import('./pages/inbox-redirect').then(m => m.InboxRedirect) },
-        path: 'inbox',
+      { path: 'folder/:id', loadComponent: () => import('./pages/folder/folder.page').then(m => m.FolderPage) },
-        loadComponent: () => import('./components/inbox/inbox.component'),
+      { path: 'message/:id', loadComponent: () => import('./pages/message/message.page').then(m => m.MessagePage) },
-      },
+      { path: 'compose', loadComponent: () => import('./pages/compose/compose.page').then(m => m.ComposePage) },
-      {
+      { path: 'contacts', loadComponent: () => import('./pages/contacts/contacts.page').then(m => m.ContactsPage) },
-        path: 'compose',
+      { path: 'blocked', loadComponent: () => import('./pages/blocked/blocked.page').then(m => m.BlockedPage) },
-        loadComponent: () => import('./components/compose/compose.component'),
+      { path: 'settings', loadComponent: () => import('./pages/settings/settings.page').then(m => m.SettingsPage) }
-      },
+    ]
-      {
-        path: 'message/:id',
-        loadComponent: () => import('./components/message-detail/message-detail.component'),
-      },
-      {
-        path: 'contacts',
-        loadComponent: () => import('./components/contacts/contacts.component'),
-      },
-      {
-        path: '',
-        redirectTo: 'inbox',
-        pathMatch: 'full',
-      },
-    ],
-  },
-  {
-    path: '**',
-    redirectTo: 'login',
   },
+  { path: '**', redirectTo: '' }
 ];
+

frontend/src/app/app.ts

@@ -1,10 +1,14 @@
-import { Component } from '@angular/core';
+import { Component, inject } from '@angular/core';
 import { RouterOutlet } from '@angular/router';
+import { OverlaysComponent } from './ui/overlays.component';
+import { ThemeService } from './ui/theme.service';
 
 @Component({
-  imports: [RouterOutlet],
+  imports: [RouterOutlet, OverlaysComponent],
   selector: 'app-root',
-  template: `<router-outlet />`,
+  template: `<router-outlet /><app-overlays />`
-  styles: ``
 })
-export class App {}
+export class App {
+  // applies the remembered palette before the first page renders
+  private theme = inject(ThemeService);
+}

frontend/src/app/components/compose/compose.component.ts

@@ -1,121 +0,0 @@
-import { Component, inject } from '@angular/core';
-import { RouterLink } from '@angular/router';
-import { FormsModule } from '@angular/forms';
-import { MailService } from '../../services/mail.service';
-import { Router, ActivatedRoute } from '@angular/router';
-
-@Component({
-  selector: 'app-compose',
-  standalone: true,
-  imports: [RouterLink, FormsModule],
-  providers: [MailService],
-  template: `
-    <div class="glass-panel p-6">
-      <h2 class="text-lg font-orbitron font-bold text-cyan-500 mb-6 flex items-center gap-2">
-        <i class="fa-solid fa-pen-to-square text-pink-500"></i> COMPOSE MESSAGE
-      </h2>
-
-      @if (success) {
-        <div class="mb-4 p-3 rounded-lg bg-cyan-500/20 border border-cyan-500/40 text-cyan-500 text-sm font-mono">
-          Message sent successfully!
-        </div>
-      }
-
-      <form (ngSubmit)="onSend()" class="space-y-4">
-        <div>
-          <label for="to" class="block text-xs font-mono text-cyan-500 mb-1">TO</label>
-          <input id="to" type="email" [(ngModel)]="to" name="to" required
-            class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-3 text-sm text-slate-200 font-mono focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-500 transition-all"
-            placeholder="recipient@example.com">
-        </div>
-
-        <div>
-          <label for="subject" class="block text-xs font-mono text-cyan-500 mb-1">SUBJECT</label>
-          <input id="subject" type="text" [(ngModel)]="subject" name="subject" required
-            class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-3 text-sm text-slate-200 font-mono focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-500 transition-all"
-            placeholder="Enter subject...">
-        </div>
-
-        <div>
-          <div class="flex items-center justify-between mb-1">
-            <label for="body" class="text-xs font-mono text-cyan-500">BODY</label>
-            <label class="flex items-center gap-2 cursor-pointer">
-              <span class="text-xs font-mono text-slate-400">HTML</span>
-              <input type="checkbox" [(ngModel)]="isHtml" name="isHtml" class="sr-only">
-              <span class="w-10 h-5 rounded-full bg-slate-900/50 border border-cyan-500/30 relative transition-all"
-                [class.bg-cyan-500/30]="isHtml" [class.border-cyan-500]="isHtml">
-                <span class="absolute top-0.5 left-0.5 w-3.5 h-3.5 rounded-full bg-cyan-500 transition-all"
-                  [class.translate-x-5]="isHtml"></span>
-              </span>
-            </label>
-          </div>
-          <textarea id="body" [(ngModel)]="body" name="body" rows="10" required
-            class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-3 text-sm text-slate-200 font-mono focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-500 transition-all resize-none"
-            [placeholder]="isHtml ? 'Write HTML or Markdown...' : 'Write your message...'"></textarea>
-          @if (isHtml) {
-            <p class="text-xs text-slate-500 font-mono mt-1"><i class="fa-solid fa-lightbulb mr-1"></i>Supports Markdown: **bold**, *italic*, - lists, &nbsp;code&nbsp;</p>
-          }
-        </div>
-
-        <div class="flex gap-3 pt-4">
-          <button type="submit" [disabled]="sending"
-            class="cyber-btn px-8 py-3 rounded-xl text-sm font-bold">
-            <i class="fa-solid fa-paper-plane mr-1"></i> {{ sending ? 'SENDING...' : 'SEND' }}
-          </button>
-          <a routerLink="/inbox" class="px-6 py-3 rounded-xl text-xs font-mono text-slate-400 border border-slate-600 hover:text-slate-200 hover:border-slate-400 transition-all text-center">
-            CANCEL
-          </a>
-        </div>
-      </form>
-    </div>
-  `,
-  styles: ``
-})
-export default class ComposeComponent {
-  private mailService = inject(MailService);
-  private router = inject(Router);
-  private route = inject(ActivatedRoute);
-
-  to = '';
-  subject = '';
-  body = '';
-  isHtml = false;
-  sending = false;
-  success = false;
-
-  constructor() {
-    // Поддержка Reply и Forward через queryParams
-    this.route.queryParams.subscribe(params => {
-      if (params['replyTo']) {
-        this.to = params['replyTo'];
-      }
-      if (params['subject']) {
-        this.subject = params['subject'];
-      }
-      if (params['forwardSubject']) {
-        this.subject = params['forwardSubject'];
-      }
-      if (params['forwardBody']) {
-        this.body = '\n\n--- Forwarded message ---\n' + params['forwardBody'];
-      }
-    });
-  }
-
-  onSend(): void {
-    this.sending = true;
-    this.mailService.send({ to: this.to, subject: this.subject, body: this.body, html: this.isHtml }).subscribe({
-      next: () => {
-        this.success = true;
-        this.sending = false;
-        this.to = '';
-        this.subject = '';
-        this.body = '';
-        this.isHtml = false;
-        setTimeout(() => this.router.navigate(['/inbox']), 1500);
-      },
-      error: () => {
-        this.sending = false;
-      }
-    });
-  }
-}

frontend/src/app/components/contacts/contacts.component.html

@@ -1,102 +0,0 @@
-<div class="space-y-4">
-  <h2 class="text-lg font-orbitron font-bold text-cyan-300 flex items-center gap-2">
-    <i class="fa-solid fa-users text-pink-500"></i> CONTACTS
-    <span class="text-sm font-mono text-slate-400 ml-auto">{{ contacts().length }} contacts</span>
-  </h2>
-
-  <!-- Форма добавления -->
-  <div class="glass-panel p-5">
-    <h3 class="text-sm font-orbitron font-bold text-yellow-400 mb-3 flex items-center gap-2">
-      <i class="fa-solid fa-pen-to-square text-pink-500"></i> {{ editingContact() ? 'EDIT CONTACT' : 'ADD NEW CONTACT' }}
-    </h3>
-    <form (ngSubmit)="saveContact()" class="grid grid-cols-1 md:grid-cols-2 gap-3">
-      <div>
-        <label class="block text-xs font-mono text-pink-400 mb-1">NAME</label>
-        <input type="text" [(ngModel)]="formName" name="name"
-          class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-2.5 text-sm font-mono text-slate-200 focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-400 transition-all"
-          placeholder="John Doe">
-      </div>
-      <div>
-        <label class="block text-xs font-mono text-pink-400 mb-1">EMAIL *</label>
-        <input type="email" [(ngModel)]="formEmail" name="email" required
-          class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-2.5 text-sm font-mono text-slate-200 focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-400 transition-all"
-          placeholder="john@example.com">
-      </div>
-      <div>
-        <label class="block text-xs font-mono text-pink-400 mb-1">PHONE</label>
-        <input type="text" [(ngModel)]="formPhone" name="phone"
-          class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-2.5 text-sm font-mono text-slate-200 focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-400 transition-all"
-          placeholder="+1 234 567 8900">
-      </div>
-      <div>
-        <label class="block text-xs font-mono text-pink-400 mb-1">COMPANY</label>
-        <input type="text" [(ngModel)]="formCompany" name="company"
-          class="w-full bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-2.5 text-sm font-mono text-slate-200 focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-400 transition-all"
-          placeholder="Acme Corp">
-      </div>
-      <div class="md:col-span-2 flex gap-2">
-        <button type="submit"
-          class="cyber-btn px-6 py-2 rounded-xl text-xs font-bold">
-          @if (editingContact()) {
-            <i class="fa-solid fa-save mr-1"></i> UPDATE
-          } @else {
-            <i class="fa-solid fa-plus mr-1"></i> ADD
-          }
-        </button>
-        @if (editingContact()) {
-          <button type="button" (click)="cancelEdit()"
-            class="px-4 py-2 rounded-xl text-xs font-mono text-slate-400 border border-slate-600/40 hover:text-slate-200 hover:border-slate-400 transition-all">
-            <i class="fa-solid fa-xmark mr-1"></i> CANCEL
-          </button>
-        }
-      </div>
-    </form>
-  </div>
-
-  <!-- Список контактов -->
-  <div class="glass-panel p-5">
-    @if (contacts().length === 0) {
-      <div class="text-center py-12 text-slate-400 font-mono">
-        <i class="fa-solid fa-address-card text-4xl mb-4 text-slate-600"></i>
-        <p>No contacts yet</p>
-      </div>
-    } @else {
-      <div class="space-y-2">
-        @for (contact of contacts(); track contact.id) {
-          <div class="flex items-center gap-3 p-3 rounded-xl border border-cyan-500/10 hover:border-cyan-500/40 hover:bg-cyan-500/5 transition-all">
-            <div class="w-10 h-10 rounded-full bg-purple-500/30 flex items-center justify-center text-cyan-400 font-bold text-lg">
-              {{ (contact.name || contact.email).charAt(0).toUpperCase() }}
-            </div>
-            <div class="flex-1 min-w-0">
-              <div class="font-mono text-slate-200 truncate">{{ contact.name || '(No name)' }}</div>
-              <div class="text-xs text-slate-400 font-mono truncate">{{ contact.email }}</div>
-              @if (contact.phone || contact.company) {
-                <div class="text-xs text-slate-500 font-mono">
-                  @if (contact.company) {
-                    {{ contact.company }}
-                  }
-                  @if (contact.company && contact.phone) {
-                    &nbsp;•&nbsp;
-                  }
-                  @if (contact.phone) {
-                    {{ contact.phone }}
-                  }
-                </div>
-              }
-            </div>
-            <div class="flex gap-1">
-              <button (click)="editContact(contact)"
-                class="px-2 py-1 text-xs font-mono text-cyan-400 hover:bg-cyan-500/10 rounded-lg transition-all">
-                <i class="fa-solid fa-pen"></i>
-              </button>
-              <button (click)="deleteContact(contact.id!)"
-                class="px-2 py-1 text-xs font-mono text-pink-400 hover:bg-pink-500/10 rounded-lg transition-all">
-                <i class="fa-solid fa-trash"></i>
-              </button>
-            </div>
-          </div>
-        }
-      </div>
-    }
-  </div>
-</div>

frontend/src/app/components/contacts/contacts.component.ts

@@ -1,94 +0,0 @@
-import { Component, inject, signal } from '@angular/core';
-import { FormsModule } from '@angular/forms';
-import { MailService } from '../../services/mail.service';
-import { Contact } from '../../models/mail.models';
-
-@Component({
-  selector: 'app-contacts',
-  standalone: true,
-  imports: [FormsModule],
-  providers: [MailService],
-  templateUrl: './contacts.component.html',
-  styles: ``
-})
-export default class ContactsComponent {
-  private mailService = inject(MailService);
-
-  contacts = signal<Contact[]>([]);
-  editingContact = signal<Contact | null>(null);
-
-  formName = '';
-  formEmail = '';
-  formPhone = '';
-  formCompany = '';
-
-  constructor() {
-    this.loadContacts();
-  }
-
-  loadContacts(): void {
-    this.mailService.getContacts().subscribe({
-      next: (contacts) => this.contacts.set(contacts),
-      error: (e) => console.error('Failed to load contacts', e)
-    });
-  }
-
-  saveContact(): void {
-    if (!this.formEmail.trim()) return;
-
-    const contact: Contact = {
-      name: this.formName.trim(),
-      email: this.formEmail.trim(),
-      phone: this.formPhone.trim() || undefined,
-      company: this.formCompany.trim() || undefined
-    };
-
-    if (this.editingContact()?.id) {
-      this.mailService.updateContact(this.editingContact()!.id!, contact).subscribe({
-        next: () => {
-          this.resetForm();
-          this.loadContacts();
-        },
-        error: (e) => console.error('Failed to update contact', e)
-      });
-    } else {
-      this.mailService.addContact(contact).subscribe({
-        next: () => {
-          this.resetForm();
-          this.loadContacts();
-        },
-        error: (e) => console.error('Failed to add contact', e)
-      });
-    }
-  }
-
-  editContact(contact: Contact): void {
-    this.editingContact.set(contact);
-    this.formName = contact.name || '';
-    this.formEmail = contact.email || '';
-    this.formPhone = contact.phone || '';
-    this.formCompany = contact.company || '';
-  }
-
-  cancelEdit(): void {
-    this.editingContact.set(null);
-    this.resetForm();
-  }
-
-  deleteContact(id: number): void {
-    if (confirm('Delete this contact?')) {
-      this.mailService.deleteContact(id).subscribe({
-        next: () => this.loadContacts(),
-        error: (e) => console.error('Failed to delete contact', e)
-      });
-    }
-  }
-
-  resetForm(): void {
-    this.formName = '';
-    this.formEmail = '';
-    this.formPhone = '';
-    this.formCompany = '';
-    this.editingContact.set(null);
-  }
-}

frontend/src/app/components/inbox/inbox.component.ts

@@ -1,196 +0,0 @@
-import { Component, inject, signal } from '@angular/core';
-import { RouterLink, ActivatedRoute } from '@angular/router';
-import { FormsModule } from '@angular/forms';
-import { MailService } from '../../services/mail.service';
-import { Message, Folder } from '../../models/mail.models';
-import { DatePipe, SlicePipe } from '@angular/common';
-import { map, switchMap } from 'rxjs/operators';
-import { of } from 'rxjs';
-
-@Component({
-  selector: 'app-inbox',
-  standalone: true,
-  imports: [RouterLink, FormsModule, DatePipe, SlicePipe],
-  providers: [MailService],
-  template: `
-    <div class="space-y-4">
-      <!-- Поиск -->
-      <div class="glass-panel p-4">
-        <div class="flex gap-3">
-          <input [(ngModel)]="searchQuery" (keyup.enter)="loadMessages()"
-            class="flex-1 bg-slate-950/80 border border-cyan-500/40 rounded-xl px-4 py-2 text-sm text-slate-200 font-mono focus:outline-none focus:ring-2 focus:ring-pink-500 focus:border-cyan-400 transition-all"
-            placeholder="Search messages...">
-          <button (click)="loadMessages()" class="cyber-btn px-6 py-2 rounded-xl text-xs font-bold">
-            <i class="fa-solid fa-magnifying-glass mr-1"></i> SEARCH
-          </button>
-        </div>
-      </div>
-
-      <!-- Список писем -->
-      <div class="glass-panel p-4">
-        <h2 class="text-lg font-orbitron font-bold text-cyan-300 mb-4 flex items-center gap-2">
-          <i class="fa-solid fa-inbox text-pink-500"></i> {{ folderName() }}
-          <span class="text-sm font-mono text-slate-400 ml-auto">{{ messages()?.length || 0 }} messages</span>
-        </h2>
-
-        @if (!messages() || messages().length === 0) {
-          <div class="text-center py-12 text-slate-400 font-mono">
-            <i class="fa-solid fa-envelope-open-text text-4xl mb-4 text-slate-600"></i>
-            <p>No messages yet</p>
-          </div>
-        } @else {
-          <div class="space-y-2">
-            @for (msg of messages() || []; track msg.id) {
-              <a routerLink="/message/{{ msg.id }}"
-                 class="block p-4 rounded-xl border border-cyan-500/10 hover:border-cyan-500/40 hover:bg-cyan-500/5 transition-all cursor-pointer group">
-                <div class="flex items-start gap-3">
-                  <!-- Индикатор прочитанности -->
-                  <div class="mt-1">
-                    @if (!msg.read) {
-                      <span class="w-3 h-3 rounded-full bg-pink-500 inline-block shadow-[0_0_8px_rgba(255,0,127,0.8)]"></span>
-                    } @else {
-                      <span class="w-3 h-3 rounded-full border border-slate-500 inline-block"></span>
-                    }
-                  </div>
-
-                  <div class="flex-1 min-w-0">
-                    <div class="flex items-center gap-2 mb-1">
-                      <span class="font-bold text-sm text-slate-200 font-rajdhani truncate">
-                        {{ msg.senderName || msg.sender }}
-                      </span>
-                      @if (msg.spam) {
-                        <span class="px-2 py-0.5 text-xs rounded-full bg-yellow-500/20 text-yellow-400 font-mono">
-                          SPAM
-                        </span>
-                      }
-                      @if (msg.flagged) {
-                        <i class="fa-solid fa-star text-yellow-400 text-xs"></i>
-                      }
-                    </div>
-                    <div class="text-sm text-cyan-400 font-rajdhani truncate group-hover:text-pink-400 transition-colors">
-                      {{ msg.subject || '(No subject)' }}
-                    </div>
-                    <div class="text-xs text-slate-400 font-mono truncate">
-                      {{ msg.body || '' | slice:0:100 }}{{ (msg.body || '').length > 100 ? '...' : '' }}
-                    </div>
-                  </div>
-
-                  <div class="text-right flex-shrink-0">
-                    <div class="text-xs text-slate-400 font-mono">
-                      {{ msg.sentAt | date:'MMM d, HH:mm' }}
-                    </div>
-                    @if (msg.hasAttachments) {
-                      <span class="text-xs text-purple-400 font-mono"><i class="fa-solid fa-paperclip mr-1"></i>{{ msg.attachmentCount }}</span>
-                    }
-                  </div>
-                </div>
-              </a>
-            }
-          </div>
-        }
-      </div>
-
-      <!-- Пагинация -->
-      @if (totalPages() > 1) {
-        <div class="glass-panel p-4 flex items-center justify-center gap-2">
-          <button (click)="goToPage(page() - 1)" [disabled]="page() === 0"
-            class="px-3 py-1 rounded-lg text-xs font-mono text-cyan-400 border border-cyan-500/30 hover:bg-cyan-500/10 disabled:opacity-30 disabled:cursor-not-allowed transition-all">
-            <i class="fa-solid fa-chevron-left mr-1"></i> Prev
-          </button>
-          @for (p of pageNumbers; track p) {
-            <button (click)="goToPage(p)"
-              [class.bg-pink-500/20]="p === page()" [class.text-pink-400]="p === page()"
-              [class.border-pink-500]="p === page()"
-              class="px-3 py-1 rounded-lg text-xs font-mono text-slate-400 border border-cyan-500/20 hover:bg-cyan-500/10 hover:text-cyan-300 transition-all">
-              {{ p + 1 }}
-            </button>
-          }
-          <button (click)="goToPage(page() + 1)" [disabled]="page() >= totalPages() - 1"
-            class="px-3 py-1 rounded-lg text-xs font-mono text-cyan-400 border border-cyan-500/30 hover:bg-cyan-500/10 disabled:opacity-30 disabled:cursor-not-allowed transition-all">
-            Next <i class="fa-solid fa-chevron-right ml-1"></i>
-          </button>
-          <span class="text-xs font-mono text-slate-500 ml-2">
-            Page {{ page() + 1 }} of {{ totalPages() }}
-          </span>
-        </div>
-      }
-    </div>
-  `,
-  styles: ``
-})
-export default class InboxComponent {
-  private route = inject(ActivatedRoute);
-  private mailService = inject(MailService);
-  messages = signal<Message[]>([]);
-  folderName = signal<string>('INBOX');
-  searchQuery = '';
-  folderId = signal<number>(1);
-  page = signal<number>(0);
-  totalPages = signal<number>(1);
-  pageSize = 20;
-
-  constructor() {
-    // Подписываемся на изменения folderId в queryParams
-    this.route.queryParams.subscribe(params => {
-      const newFolderId = params['folderId'] ? Number(params['folderId']) : 1;
-      if (newFolderId !== this.folderId()) {
-        this.folderId.set(newFolderId);
-        this.loadFolderName(newFolderId);
-        this.loadMessages();
-      }
-    });
-    // Начальная загрузка
-    const initialFolderId = this.route.snapshot.queryParams['folderId'] ? Number(this.route.snapshot.queryParams['folderId']) : 1;
-    this.folderId.set(initialFolderId);
-    this.loadFolderName(initialFolderId);
-    this.loadMessages();
-  }
-
-  loadFolderName(folderId: number): void {
-    this.mailService.getFolders().subscribe({
-      next: (folders) => {
-        const folder = folders.find(f => f.id === folderId);
-        this.folderName.set(folder ? folder.name : 'INBOX');
-      },
-      error: () => this.folderName.set('INBOX')
-    });
-  }
-
-  loadMessages(): void {
-    const currentFolderId = this.folderId();
-    const currentPage = this.page();
-    if (this.searchQuery.trim()) {
-      this.mailService.searchMessages(currentFolderId, this.searchQuery.trim()).subscribe({
-        next: (msgs) => this.messages.set(msgs),
-        error: () => console.error('Search failed')
-      });
-    } else {
-      this.mailService.getMessages(currentFolderId, currentPage, this.pageSize).subscribe({
-        next: (result) => {
-          this.messages.set(result.content);
-          this.totalPages.set(result.totalPages);
-        },
-        error: () => console.error('Failed to load messages')
-      });
-    }
-  }
-
-  goToPage(page: number): void {
-    if (page >= 0 && page < this.totalPages()) {
-      this.page.set(page);
-      this.loadMessages();
-    }
-  }
-
-  get pageNumbers(): number[] {
-    const pages: number[] = [];
-    const total = this.totalPages();
-    const current = this.page();
-    const start = Math.max(0, current - 2);
-    const end = Math.min(total - 1, current + 2);
-    for (let i = start; i <= end; i++) {
-      pages.push(i);
-    }
-    return pages;
-  }
-}