ietf-imap-mcp

An MCP server for navigating IETF mailing-list archives over the IETF IMAP service (imap.ietf.org:993). It lets an MCP-capable assistant search, page through, and read list traffic — handy when chairing a working group or BoF and you need to track what the list is actually saying.

Built to be a good citizen of shared IETF infrastructure. See Respecting IETF resources.

Tools

Tool	What it does
list_mailing_lists(pattern, limit)	Discover list mailboxes (IMAP LIST).
search_list(list_name, subject, from_addr, text, since, before, limit)	Search a list; returns message summaries, newest first.
page_list(list_name, offset, limit)	Page through a list's messages, newest first.
get_message(list_name, uid, include_body, max_body_chars)	Fetch one message (headers + plain-text body) by UID.

Configuration

All configuration is via environment variables — no credentials are ever stored in the code or the repo.

Variable	Purpose	Default
IETF_IMAP_USER	anonymous, or your Datatracker username	anonymous
IETF_IMAP_EMAIL	Email used as the password for anonymous access	—
IETF_IMAP_PASSWORD	Datatracker password (authenticated access) — plaintext	—
IETF_IMAP_PASSWORD_CMD	Shell command whose stdout is the password (e.g. op read …)	—
IETF_IMAP_PASSWORD_FILE	Path to a file containing the password	—
IETF_IMAP_MIN_INTERVAL	Minimum seconds between IMAP commands	1.0
IETF_IMAP_MAILBOX_PREFIX	Prefix for bare list names	Shared Folders/

See .env.example for a copy-paste starting point.

Authentication

Per the IETF lists page, the IMAP service supports two modes.

Anonymous (recommended for public lists)

IMAP anonymous login uses your email address in the password field — this is not a secret. This is all you need for public list archives:

{
  "mcpServers": {
    "ietf-imap": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/ietf-imap-mcp", "python", "-m", "ietf_imap_mcp"],
      "env": { "IETF_IMAP_USER": "anonymous", "IETF_IMAP_EMAIL": "you@example.org" }
    }
  }
}

Authenticated (Datatracker — only when anonymous is not possible)

Set IETF_IMAP_USER to your Datatracker username and supply the password. The password is resolved in this order of preference: IETF_IMAP_PASSWORD → IETF_IMAP_PASSWORD_CMD → IETF_IMAP_PASSWORD_FILE.

⚠️ Keep the secret out of the config file. Values in an MCP client's env block sit in plaintext on disk (and often sync to the cloud). Prefer IETF_IMAP_PASSWORD_CMD (resolve from a secret manager at launch) or IETF_IMAP_PASSWORD_FILE (a chmod 600 file). Avoid IETF_IMAP_PASSWORD except for throwaway local testing, and never put a real password in a file you commit.

Recommended — resolve from a secret manager (no secret on disk):

{
  "mcpServers": {
    "ietf-imap": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/ietf-imap-mcp", "python", "-m", "ietf_imap_mcp"],
      "env": {
        "IETF_IMAP_USER": "your-datatracker-username",
        "IETF_IMAP_PASSWORD_CMD": "op read \"op://Private/IETF Datatracker/password\""
      }
    }
  }
}

(op is the 1Password CLI; substitute pass, gopass, security find-generic-password, vault kv get, etc.)

Alternative — a permission-restricted file:

install -m 600 /dev/null ~/.config/ietf-imap/datatracker.pw
printf '%s' 'your-password' > ~/.config/ietf-imap/datatracker.pw

"env": {
  "IETF_IMAP_USER": "your-datatracker-username",
  "IETF_IMAP_PASSWORD_FILE": "~/.config/ietf-imap/datatracker.pw"
}

Run

uv run ietf-imap-mcp          # stdio MCP server
# or
uv run python -m ietf_imap_mcp

Respecting IETF resources

The IMAP server is shared infrastructure. This server:

• Read-only — mailboxes are opened with EXAMINE, never SELECT; it cannot flag, move, or delete anything.
• Rate-limited — a minimum interval (default 1s) is enforced between IMAP commands.
• Bounded — result counts are hard-capped (≤ 100 per call) so one call can't pull thousands of messages.
• Connection-reusing — one TLS connection is kept open rather than reconnecting per call.

Please don't lower the interval or remove the caps to hammer the service. For bulk needs, use rsync archive downloads instead.

Development

uv run pytest        # tests are fully mocked — no network, no live IMAP

License

MIT © 2026 Orie Steele