Multimail MCP Server

@multimail/mcp-server

MCP server for MultiMail. Give your agent its own email address with graduated human oversight — from full approval to autonomous sending.

Quick start

npx @multimail/mcp-server

Set MULTIMAIL_API_KEY for full access, or run without it to create an account first. Get a key at multimail.dev.

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

Getting Started

Don't have an account yet? Two options:

Option A: Browser signup (recommended, 60 seconds)

1. Go to multimail.dev/pricing
2. Click Get started free (or pick a paid plan)
3. Choose what your agent will do and pick an oversight mode
4. Check your email for the activation code
5. Add the API key to your MCP config below

Option B: Remote MCP server (auto-signup via OAuth)

Add this to your MCP client — signup happens in the browser when you first connect:

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

After signup: configure your mailbox

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.

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

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