For developers

Email for AI agents, done privately.

A native MCP server over the open JMAP standard. A real, EU-hosted mailbox your agents can drive — not a throwaway inbox, and not a US data trail. Sending is always pinned to the mailbox itself.

npm: @lettio/mcp GitHub MCP Registry

Hosted (OAuth)

Add the remote server in your MCP client and sign in. Nothing to install. 

https://mcp.lettio.eu/mcp

Streamable HTTP · OAuth 2.1 · one token, one mailbox.

Local (stdio)

Run it on your own machine — e.g. in a Claude Desktop config: 

{
  "mcpServers": {
    "lettio": {
      "command": "npx",
      "args": ["-y", "@lettio/mcp"],
      "env": {
        "LETTIO_USERNAME": "you@yourcompany.eu",
        "LETTIO_PASSWORD": "your-app-password"
      }
    }
  }
}

The tools your agent gets

  • list_recent_emails
  • search_emails
  • read_email
  • list_mailboxes
  • send_email
  • reply_email
  • set_read_status
  • flag_email
  • move_email
  • whoami

Read and search the inbox, reply in-thread, organise — and send. Sending is pinned to the signed-in mailbox, so an agent can never send from another address. Works with Claude, Cursor and any MCP client.

Lettio for Developers

Usage-based, and private by default.

Spin up mailboxes your agents operate, pay for what they actually use, and keep EU data residency for your users from the first call — not as an enterprise upsell. A full private mailbox behind the API, not a bare relay.

  • Inboxes on demand, by API
  • MCP server, agent-ready
  • EU data residency for your users
  • Send only as the mailbox itself
  • Scales with usage

Developer pricing is usage-based — join the waitlist for early access and founding rates.

Early access

Be early to European AI email.

We're building Lettio now. Join the waitlist to get in first — with a founding price that stays.