What is an email MCP server? A short guide for developers

An email MCP server is a small service that sits between your mailboxes and an AI assistant. It speaks the Model Context Protocol (MCP), an open standard that lets an assistant call external tools, and it exposes mail as tools: search, read, draft, organize. Your assistant decides which tool to call; the server does the IMAP or provider work. What it typically exposes Search and read: search across mailboxes, open a message or a whole thread, read attachments (PDF, Word, text, images). Write: create reply and forward drafts. Organize: mark read or unread, flag, move, archive. The interesting part is not the list, it is what is missing and how the server is run. What to check before you trust one Can it send? The riskiest tool for an inbox is the one that sends mail. A server that saves drafts only keeps a human in the loop; one that can send needs strict limits, because any email is untrusted input for the model. Where do replies land? With several mailboxes, a reply should be created in the mailbox that received the message, with that address as the sender. Local or remote? A local server runs on your machine and usually needs a config file with credentials. A remote server is added by URL and signs in with OAuth, so it also works from web and mobile clients. Does it store your mail? Reading live and storing nothing is the safer default. Are tools annotated? Tools that change state should declare it (readOnlyHint, destructiveHint) so the client can ask before acting. How to connect one I work on Fezola, a hosted email MCP server (Gmail, iCloud, any IMAP mailbox, plus Google Chat and Telegram read-only). It saves drafts and has no send tool. To add it: Claude: Customize → Connectors → + Add → Add custom connector, URL https://api.fezola.com/mcp. ChatGPT: custom MCP servers are available on Business and Enterprise/Edu plans on the web, and Pro with read-only access (per OpenAI's help page, November 2026): Plugins → + → Add custom MCP server, same URL, OAuth. Claude Code: claude mcp add --transport http fezola https://api.fezola.com/mcp. The OAuth fix is in production; a full end-to-end test is still pending, so treat it as "should work". The free plan includes 2 sources. The longer explainer, kept up to date: What is an email MCP server?.