awita-mail

Secure, draft-first MCP access to a GMX business mailbox. The service uses IMAP for mailbox operations, SMTP STARTTLS for delivery, and Streamable HTTP at /mcp. Email content is always untrusted external data.

Start locally

Use Python 3.12 and a GMX application-specific password (never the normal account password). GMX defaults are imap.gmx.com:993 TLS and mail.gmx.com:587 STARTTLS.

python3.12 -m venv .venv
. .venv/bin/activate
python -m pip install -e '.[dev]'
cp .env.example .env
# Edit .env: GMX_EMAIL, GMX_APP_PASSWORD, MCP_HOSTNAME, MCP_API_TOKEN
python -m app
curl -i http://127.0.0.1:8000/health

The package includes a pinned CA bundle fallback for Python installations that do not expose the macOS/system trust store (for example, a fresh python.org installation). If this virtual environment already existed before that dependency was added, run python -m pip install -e '.[dev]' again.

Generate a strong token with python -c "import secrets; print(secrets.token_urlsafe(48))". .env is Git-ignored. The MCP endpoint requires Authorization: Bearer $MCP_API_TOKEN:

curl -i -X POST http://127.0.0.1:8000/mcp \
  -H "Authorization: Bearer $MCP_API_TOKEN" \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  --data '{"jsonrpc":"2.0","id":1,"method":"ping"}'

Related MCP server: Gmail MCP Server

Docker

The container exposes no host port, runs non-root, drops capabilities, and persists its SQLite audit ledger in /data.

cp .env.example .env
# Set MCP_HOSTNAME, GMX credentials, MCP_API_TOKEN, and your Traefik network.
docker compose build
docker compose up -d
docker compose ps
docker compose logs --tail=100 awita-mail

Set TRAEFIK_ENABLE=true only after DNS/TLS are ready. Keep ALLOW_SEND=false until the draft workflow is verified. Prefer GMX_APP_PASSWORD_FILE and MCP_API_TOKEN_FILE in a deployment-specific Compose secret override; never put secret contents in images, labels, or logs.

For a local Docker-only smoke test, publish only loopback with the debug override:

docker network create proxy 2>/dev/null || true
docker compose -f docker-compose.yml -f docker-compose.debug.yml up --build

Stop it with Ctrl-C; the normal Compose file remains unpublished to the host.

Test

Tests never contact GMX; mail boundaries are mocked/injectable.

. .venv/bin/activate
pytest
ruff format --check .
ruff check .
mypy app
python -m build

For interactive protocol testing, run the current MCP Inspector against http://127.0.0.1:8000/mcp with the bearer token. Call list_folders and check_gmx_connectivity first. The live folder mapping is account-specific, so do not assume English Sent/Drafts names.

Tools and sending

The tools are: list_folders, list_emails, search_emails, read_email, list_attachments, download_attachment, create_draft, create_reply_draft, update_draft, delete_draft, send_draft, mark_as_read, mark_as_unread, and check_gmx_connectivity. There is no arbitrary send, arbitrary deletion, forwarding rule, bulk operation, or move tool.

The only send workflow is read/search → create draft → user reviews → user explicitly requests send → send_draft. ALLOW_SEND=false blocks SMTP. Configure Codex write approval:

[mcp_servers.awita_mail]
url = "https://mcp.example.com/mcp"
bearer_token_env_var = "AWITA_MAIL_MCP_TOKEN"
default_tools_approval_mode = "writes"

[mcp_servers.awita_mail.tools.send_draft]
approval_mode = "prompt"

[mcp_servers.awita_mail.tools.delete_draft]
approval_mode = "prompt"

Export AWITA_MAIL_MCP_TOKEN for Codex and restart the desktop app/IDE extension. CLI alternative: codex mcp add awita_mail --url https://mcp.example.com/mcp --bearer-token-env-var AWITA_MAIL_MCP_TOKEN.

All email-derived fields are explicitly untrusted and cannot authorize a tool call. Attachment downloads are bounded inert MCP blobs; they are never executed or extracted. The durable SQLite ledger prevents successful send replay and records sanitized audit fields only.

ChatGPT later

ChatGPT custom MCP apps need a remotely reachable endpoint and supported authentication. For a private/on-premises server, use Secure MCP Tunnel. For direct public integration, replace the static bearer layer with a real OAuth/OIDC authorization server and MCP protected-resource metadata with refresh tokens. Mail logic and safeguards are already independent of authentication.

Configuration

GMX_EMAIL, GMX_APP_PASSWORD[_FILE], MCP_API_TOKEN[_FILE], MCP_HOSTNAME, MCP_PORT, MCP_BIND_HOST, ALLOW_SEND, LOG_LEVEL, IMAP_*, SMTP_*, MAIL_TIMEOUT_SECONDS, the MAX_* limits, AUDIT_DB_PATH, TRAEFIK_*, and FORWARDED_ALLOW_IPS are documented in .env.example. ALLOW_SEND defaults false; MAX_EMAIL_RESULTS is capped at 100. The service never logs credentials, Authorization headers, or full bodies.