Fastmail MCP Server

An MCP server to connect to Fastmail, or other jmap-based email services

User Setup

1. Clone this repository

   git clone https://github.com/gnapse/fastmail-mcp
   

2. Install dependencies and set up environment

   npm run setup
   

3. Add this fastmail-mcp section to your mcp.json config in Cursor, Claude, Raycast, etc.

   {
       "mcpServers": {
           "fastmail-mcp": {
               "type": "stdio",
               "command": "node",
               "args": [
                   "/Users/<your_user_name>/code/fastmail-mcp/dist/mcp-server.js"
               ],
               "env": {
                   "JMAP_BEARER_TOKEN": "your-jmap-bearer-token-here",
                   "JMAP_SESSION_URL": "https://api.fastmail.com/jmap/session"
               }
           }
       }
   }
   

4. Update the configuration above as follows

   • Replace JMAP_BEARER_TOKEN with your Fastmail API token (or that of any other JMAP email provider)
   • (Optional) Replace JMAP_SESSION_URL if you're using an email provider other than Fastmail
   • Replace the path in the args array with the correct path to where you cloned the repository

Features

This project is in its early stages. Expect more and/or better tools soon.

Nevertheless, our goal is to provide a small set of tools that enable complete workflows, rather than just atomic actions, striking a balance between flexibility and efficiency for LLMs.

Available Tools

• list-mailboxes: List all mailboxes, with their IDs, names, roles, and total and unread email counts
• search-threads: Search for email threads by subject, sender, recipients, body, and more
• list-threads: List the email threads in a mailbox, or all threads from all mailboxes
• list-thread-messages: List the emails in a thread (conversation)
• get-email-details: Get details about an email
• move-threads-to-mailbox: Move all emails in one or more threads to a target mailbox
• mark-threads-read: Mark all emails in one or more threads as read
• mark-thread-unread: Mark emails in a thread as unread (all or just the last)
• archive-threads: Move all emails in one or more threads to the Archive mailbox
• delete-threads: Move all emails in one or more threads to the Trash mailbox (soft delete)

Dependencies

• MCP server using the official @modelcontextprotocol/sdk
• JMAP email access via jmap-jam

Development Setup

1. Install dependencies and set up environment

   npm run setup
   

2. Configure environment variables Update the .env file with your JMAP credentials:

   JMAP_BEARER_TOKEN=your-jmap-bearer-token-here
   JMAP_SESSION_URL=https://api.fastmail.com/jmap/session
   

3. Run the MCP server with inspector

   npm run dev
   

If you make changes to the code locally, you need to update the build:

npm run build