@multimail/mcp-server

MCP server for MultiMail. Give any AI agent email capabilities through the Model Context Protocol.

Quick start

npx @multimail/mcp-server

Requires MULTIMAIL_API_KEY environment variable. Get one at multimail.dev.

By using MultiMail you agree to the Terms of Service and Acceptable Use Policy.

Setup

Option A: Remote server (recommended)

No install required. Connect directly to our hosted server. Authenticates via OAuth in the browser.

{
  "mcpServers": {
    "multimail": {
      "type": "url",
      "url": "https://mcp.multimail.dev/mcp"
    }
  }
}

Works with Claude.ai, Claude Desktop, Claude Code, and any client that supports remote MCP servers.

Option B: Local server (stdio)

Run the server locally. API key is passed as an environment variable.

{
  "mcpServers": {
    "multimail": {
      "command": "npx",
      "args": ["-y", "@multimail/mcp-server"],
      "env": {
        "MULTIMAIL_API_KEY": "mm_live_...",
        "MULTIMAIL_MAILBOX_ID": "01KJ1NHN8J..."
      }
    }
  }
}

Where to add this

Environment variables

First-run setup

On first use, MultiMail will prompt you to configure your mailbox. You can also run this explicitly using the configure_mailbox tool:

• Oversight mode: How much human approval is required (gated_send, monitored, autonomous, etc.)
• Display name: Sender name shown in emails
• CC/BCC defaults: Automatically copy addresses on all outbound emails
• Scheduling: Enable/disable scheduled send and set default gate timing
• Signature: Email signature block

If you skip this step, MultiMail will remind you on your first tool call.

Tools

How it works

• You write email bodies in markdown. MultiMail converts to formatted HTML for delivery.
• Incoming email arrives as clean markdown. No HTML parsing or MIME decoding.
• Threading is automatic. Reply to an email and headers are set correctly.
• Sends return pending_scan status while the email is scanned for threats. If your mailbox uses gated oversight, the status transitions to pending_send_approval for human review. Do not retry or resend.
• Verify other agents by checking the X-MultiMail-Identity signed header on received emails.

Development

npm install
npm run dev   # Run with tsx (no build needed)
npm run build # Compile TypeScript
npm start     # Run compiled version

Testing

echo '{"jsonrpc":"2.0","method":"tools/list","id":1}' | MULTIMAIL_API_KEY=mm_live_... node dist/index.js

License

MIT