Fastmail MCP is an unofficial Model Context Protocol (MCP) server developed by Madllama25, designed to enable AI assistants to interact with the Fastmail JMAP API. Built with TypeScript and running on Node.js, this server empowers AI clients like Claude Code, Codex CLI, and ChatGPT to manage email, contacts, and calendar data. It functions as an AI Agents skill, providing a structured interface for automated interactions with your Fastmail services, extending AI assistant capabilities into personal information management.

What does Fastmail MCP connect to?

Fastmail MCP connects directly to the Fastmail JMAP API, providing AI assistants access to email, contacts, and calendar data. Beyond JMAP, it also integrates with CalDAV for managing calendar events and WebDAV for specific file storage functionalities. This allows a broad interaction with the Fastmail ecosystem, categorizing Fastmail MCP as both an MCP server and an AI Agents skill.

Core features and tools

Fastmail MCP exposes a rich set of callable tools for AI assistants. These include Email Operations like list_emails, send_email, and delete_email, alongside advanced capabilities such as get_conversation_thread and bulk_email_operations. For contacts, it offers Contacts Operations including create_contact and search_contacts. Calendar Operations enable managing events with tools like create_calendar_event. Additionally, Identity & Account Management tools, such as list_sending_identities, are available.

Who is it for?

Fastmail MCP is designed for users of AI coding assistants, specifically those utilizing platforms like Claude Code, Codex CLI, and ChatGPT. It empowers these AI assistants to interact with and manage their Fastmail email, contacts, and calendar data directly. Concrete workflows include searching emails, sending replies, and scheduling events. Skip this if your AI assistant cannot integrate with MCP servers via streamable HTTP.

How to get started

The server authenticates using an API key passed as an environment variable. For example, the Fastmail API token must be set as "FASTMAIL_API_TOKEN" for interaction over streamable HTTP. Specific Fastmail CalDAV usernames, app-specific passwords, WebDAV URLs, and credentials are also required as environment variables for their respective tools.

Use cases

• Listing, searching, and filtering emails based on various criteria, including advanced searches.
• Sending emails, managing drafts, and performing bulk email operations.
• Creating, updating, and deleting contacts and calendar events.

Fastmail MCP by Madllama25 enables AI assistants to manage Fastmail email, contacts, and calendar data through a diverse set of tools. It bridges AI platforms like Claude Code and ChatGPT with your personal Fastmail services. This unofficial server provides a valuable utility for automating communications and scheduling. Try listing your mailboxes using your AI assistant's email tools.