lettio-eu/mcp

**Let your AI assistant read, search and send email from a private, EU-hosted mailbox.**
Lettio MCP is a Model Context Protocol server that connects
an AI agent (Claude, Cursor, and any other MCP client) to a Lettio
mailbox over JMAP. Your assistant can triage your inbox, find a message,
and send a reply — without your email ever leaving Europe.
- 🇪🇺 **European by default** — talks to your own EU-hosted mailbox, no third‑party middleman.
- 🔒 **Safe sending** — the server can only ever send *as the mailbox it is signed in to*. It
cannot be tricked into sending from another address.
- 📬 **Everything an agent needs** — list, search, read and send, over the open JMAP standard.
- 👥 **One or many mailboxes** — configure a single account or several.
> Prefer nothing to install? Lettio also runs as a **hosted, OAuth‑secured** MCP server at
> https://mcp.lettio.eu/mcp — add that URL in your client and sign in. This npm package is the
> **local / self‑hosted** option for people who want to run it on their own machine.
Tools
| Tool | What it does |
|------|--------------|
| list_accounts | List the mailboxes this server is configured for. |
| list_mailboxes | List folders in an account, with message and unread counts. |
| list_recent_emails | Most recent messages in a mailbox (defaults to the inbox). |
| search_emails | Free‑text search across sender, subject and body. |
| read_email | Full content of one message by id. |
| send_email | Send a plain‑text email **as the signed‑in mailbox**. |
| reply_email | Reply in‑thread (keeps the conversation), optionally reply‑all. |
| set_read_status | Mark a message read or unread. |
| flag_email | Flag (star) or unflag a message. |
| move_email | Move to a folder — archive, trash (reversible), or a folder name. |
Requirements
- Node.js 18 or newer.
- A Lettio mailbox and an **app password** for it (use a dedicated app password, not your main login).
Use with Claude Desktop
Add this to your claude_desktop_config.json:
Restart Claude Desktop; the Lettio tools appear in the tools menu.
Configuration
Configured entirely through environment variables.
Single mailbox
| Variable | Required | Description |
|----------|----------|-------------|
| LETTIO_USERNAME | yes | Full email address, e.g. you@yourcompany.eu. |
| LETTIO_PASSWORD | yes | Mailbox **app password**. |
| LETTIO_HOST | no | Mail host. Defaults to https://mail.lettio.eu. |
| LETTIO_ACCOUNT_NAME | no | Friendly name for the account (default: the username). |