Fastmail MCP Server

Fastmail MCP Server – A Bridge Between AI Assistants and Fastmail

The Fastmail MCP server solves a common pain point for developers building conversational AI: accessing rich, authenticated email data without exposing credentials or writing custom API wrappers. By implementing the Model Context Protocol, it presents Fastmail’s comprehensive email, contacts, and calendar services as a set of well‑defined tools that an AI assistant can call directly. This eliminates the need for separate authentication flows, reduces latency, and keeps sensitive data within a secure server boundary.

At its core, the server offers a robust suite of email operations. From listing mailboxes and retrieving detailed statistics to searching, filtering, and fetching individual messages with full HTML content, every common email workflow is exposed as a simple tool. Developers can also manage messages—marking read/unread, deleting, moving between folders—and perform bulk operations that process thousands of emails in a single request. Advanced features such as attachment handling, conversation threading, and multi‑criteria search provide the depth required for complex productivity tasks.

Beyond email, the server extends to contacts and calendar functionality. It allows AI assistants to list all contacts, query specific entries by ID, or search by name and address. Calendar tools let assistants enumerate calendars, fetch event details, and create new events complete with participants. An identity layer exposes available sending identities and overall account statistics, giving assistants context about the sender’s configuration.

Integration into AI workflows is straightforward: an assistant can invoke any tool, receive structured JSON responses, and use that data to compose replies, schedule meetings, or automate email triage. The server’s design ensures that sensitive tokens never leave the host environment; credentials are supplied via secure environment variables, and all communication is encrypted. This approach keeps compliance requirements in check while delivering the flexibility of real‑time data access.

Unique advantages include a dry‑run mode for bulk operations, which lets developers test changes without affecting real messages. The server also bundles a ready‑made Desktop Extension for Claude, enabling instant deployment with encrypted token storage. For teams needing scalable email automation—such as support ticket routing, marketing campaign management, or personal productivity assistants—the Fastmail MCP server offers a turnkey solution that blends security, performance, and developer ergonomics.