mail-mcp

Generic IMAP+SMTP MCP server for AI agents — v0.2.4

Connect any email account to any AI agent (Claude, Gemini, Codex, Copilot, Vibe…). Intent-first design: high-level tools matching real user workflows, backed by a clean IMAP/SMTP core and a full triple admin surface (CLI + HTTP + Telegram).

Problem: AI agents have no native email access.
Why:     IMAP+SMTP are universal, server-agnostic, no OAuth2 dance required.
How:     FastMCP tools layer, pure stdlib SMTP, imapclient for IMAP, bw-env secrets.
Admin:   mail-admin CLI  +  /admin/* HTTP routes  +  Telegram bot  +  SSH exec.

Repos: GitHub · GitLab

---

Architecture

mail_mcp/
├── config.yaml          # Non-sensitive settings (hosts, ports, env var names)
├── config.py            # @lru_cache loader + 3-tier secret resolution + admin env
│
├── admin/
│   ├── service.py       # Shared backend: status, credentials CRUD, logs, summaries
│   ├── cli.py           # mail-admin — Typer+Rich admin CLI
│   └── telegram.py      # Telegram long-poll bot (in-process thread)
│
├── core/
│   ├── models.py        # Pydantic: Message, MessageSummary, Folder, Address…
│   ├── imap_client.py   # IMAPClient context-manager — search, fetch, flags, move
│   └── smtp_client.py   # SMTPClient — send, reply, forward, draft
│
├── tools/
│   ├── guide.py         # mail_guide() — agent orientation entry point
│   ├── read.py          # check_inbox, daily_digest, search_messages, get_thread…
│   ├── compose.py       # send_message, reply_message, forward_message, save_draft
│   └── manage.py        # list_folders, mark_messages, move/archive/delete/spam
│
├── server.py            # FastMCP root — mounts all sub-MCPs
├── http_app.py          # Starlette app: MCP + /health + /admin/* routes
├── daemon.py            # PID file lifecycle
└── cli.py               # Typer CLI: serve, serve-http, stop, status, inbox, folders

Secret resolution (3 tiers)

1. Admin env file  → /data/mail-admin.env  (Docker volume, persistent credential overrides)
2. Process env     → fastest (shell injection or MCP host)
3. bw-env login    → zsh -l -c 'printf "%s" "${VAR}"'  (Bitwarden GLOBAL_ENV_VARS)

---

Transports

Transport	URL / Command	Description
HTTP (homelab)	https://mail.kpihx-labs.com/mcp	Streamable-HTTP — production, always-on
stdio (fallback)	mail-mcp serve	Direct process — local dev or when HTTP down

---

Supported accounts

Account	IMAP	SMTP	Server
Polytechnique (X)	webmail.polytechnique.fr:993 TLS	:587 STARTTLS	Zimbra

More accounts: add an entry in config.yaml — no code change needed.

---

Quick start

# Install (editable for live dev)
uv tool install --editable .

# Admin CLI
mail-admin status          # credential status table
mail-admin logs 20         # last 20 log lines
mail-admin credentials set poly <login> <pass>   # live update without restart
mail-admin help            # full capability map

# MCP stdio server
mail-mcp serve

# MCP HTTP server (port 8094)
mail-mcp serve-http

---

Admin surfaces

1. CLI — mail-admin

mail-admin status [--account <id>]   # Rich table: env var, value (masked), source
mail-admin logs [N]                  # tail last N lines (default 40)
mail-admin credentials set <id> <login> <pass>
mail-admin credentials unset <id>
mail-admin help                      # full capability map

2. HTTP routes

Route	Method	Description
/health	GET	Readiness probe — auth presence per account
/admin/status	GET	Full status: pid, transport, Telegram runtime, credentials
/admin/help	GET	Full capability map (CLI / HTTP / Telegram / SSH)
/admin/logs?lines=40	GET	Tail of the admin log
/admin/credentials/set	POST	Set {account_id, login, password}
/admin/credentials/unset	POST	Clear credentials for {account_id}
/mcp	GET/POST	Streamable-HTTP MCP transport

3. Telegram bot

Token env: TELEGRAM_MAIL_HOMELAB_TOKEN — auth gate: TELEGRAM_CHAT_IDS

Command	Args	Effect
/start /help	—	Full capability map
/status	[account_id]	Credential status
/health	—	Quick health summary
/urls	—	Transport URLs
/logs	[N]	Last N log lines
/credentials_set	<id> <login> <pass>	Live credential update
/credentials_unset	<id>	Clear credentials
/restart	—	Graceful service restart

4. SSH exec

docker compose exec -T mail-mcp mail-admin status
docker compose logs --tail=100 mail-mcp

---

MCP agent registration

Claude Code (~/.claude.json)

"mail-mcp": {
  "url": "https://mail.kpihx-labs.com/mcp"
},
"mail-mcp--fallback": {
  "command": "zsh",
  "args": ["-l", "-c", "/home/kpihx/.local/bin/mail-mcp serve"]
}

Codex (~/.codex/config.toml)

[mcp_servers.mail_mcp]
url = "https://mail.kpihx-labs.com/mcp"

[mcp_servers.mail_mcp_fallback]
command = "zsh"
args = ["-l", "-c", "/home/kpihx/.local/bin/mail-mcp serve"]

Vibe/Mistral (~/.vibe/config.toml)

[[mcp_servers]]
name = "mail"
transport = "http"
url = "https://mail.kpihx-labs.com/mcp"

[[mcp_servers]]
name = "mail_fallback"
transport = "stdio"
command = "zsh"
args = ["-l", "-c", "/home/kpihx/.local/bin/mail-mcp serve"]

Gemini (~/.gemini/settings.json)

"mcpServers": {
  "mail-mcp": { "url": "https://mail.kpihx-labs.com/mcp" },
  "mail-mcp--fallback": {
    "command": "zsh",
    "args": ["-l", "-c", "/home/kpihx/.local/bin/mail-mcp serve"]
  }
}

---

Tool reference

Tool	Intent
mail_guide	Agent orientation — start here
check_inbox	Unread count + last N summaries
daily_digest	Structured morning overview
list_messages	Browse a folder
get_message	Full body by UID
search_messages	Flexible search (query, sender, date, flags)
find_unread	Unread shortcut
get_thread	Full thread by Message-ID
send_message	New email (+ auto copy to Sent, optional bounce probe via verify_bounce_window_seconds)
reply_message	Reply by UID (+ auto copy to Sent, optional bounce probe via verify_bounce_window_seconds)
forward_message	Forward by UID (+ auto copy to Sent, optional bounce probe via verify_bounce_window_seconds)
save_draft	Draft to Drafts folder
list_folders	All IMAP folders
list_labels	Alias for list_folders
create_folder	Create IMAP folder
rename_folder	Rename IMAP folder
delete_folder	Delete IMAP folder
mark_messages	Seen / flagged / answered flags
move_messages	Move UIDs to folder
archive_messages	Move to Archive
trash_messages	Move to Trash
delete_messages	Permanent delete + expunge
mark_as_spam	Move to Spam/Junk
download_attachment	Download to file (default) or ingest as Base64 (ingest_base64=True)
set_labels	Alias for move_messages

---

Security

• Credentials are never stored in config.yaml — only env var names.
• Secrets live in Bitwarden (GLOBAL_ENV_VARS) and are injected via bw-env / login shell.
• Admin credential overrides persist in /data/mail-admin.env (Docker volume) — never committed.
• No OAuth2, no refresh token storage — IMAP password auth via TLS only.

---

Deployment (Docker / homelab)

See deploy/ for docker-compose.yml and .env.example.

# Required env vars
X_LOGIN=your_imap_username
X_PASS=your_imap_password
TELEGRAM_MAIL_HOMELAB_TOKEN=<bot_token>    # optional
TELEGRAM_CHAT_IDS=<comma,separated,ids>    # optional
MAIL_MCP_ADMIN_ENV_FILE=/data/mail-admin.env

GitLab CI auto-deploys master to the homelab runner via docker compose up -d --build.