Fastmail in Claude and ChatGPT: the official MCP server or Fezola?

Short answer: Fastmail has its own MCP server since April 2026, and if Fastmail is your only mailbox and you only need to read, search and draft, it is the natural first choice. If you want Fastmail next to other mailboxes in one search, need attachments read, or use Claude with more than one Fastmail account, a multi-account connector such as Fezola covers what the official server does not.

What Fastmail's official MCP server does

As of November 2026, according to Fastmail's help page:

• The endpoint is https://api.fastmail.com/mcp, added to your assistant as a custom connector, with an OAuth sign-in. No app password is needed.
• You pick access levels: read-only (search and read mail, contacts and calendars), write (draft replies, move, delete and organize mail, update contacts and calendars) and send (email on your behalf). You can combine them.
• Attachments are not supported through MCP.
• Claude does not support several Fastmail accounts on this server.
• You can remove access in Settings, Privacy and Security, Connected apps and API tokens.

This is a good option: it is made by Fastmail, it reaches your contacts and calendars too, and you control the permissions.

When a multi-account connector makes sense

The official server does one mailbox provider very well. It does not try to cover your other mailboxes. You may want a connector like Fezola if:

• Fastmail is not your only mailbox. You have a Gmail, an iCloud address, a work mailbox on your own domain or an OVH one, and you want one search across all of them, with every result naming its account.
• You need attachments. Fezola reads PDF, Word, text and image attachments.
• You use Claude with several Fastmail accounts (for example personal and a family domain).
• You want drafts only. Fezola saves replies as drafts in the mailbox that received the message, with that address as the sender. send_message exists but is off by default.

	Fastmail official server	Fezola
Fastmail mail	Yes	Yes, over IMAP and SMTP
Contacts and calendars	Yes	No, mail only for Fastmail
Other mailboxes (Gmail, iCloud, OVH, any IMAP)	No	Yes
Several Fastmail accounts in Claude	No, per Fastmail	Yes
Attachments	Not supported, per Fastmail	PDF, Word, text, images
Sending	Optional Send access level	Drafts only by default
Sign-in	OAuth with your Fastmail password	Fastmail app password, entered once in Fezola
Price	Not stated on the help page	Free for 2 sources, Pro $9 per month

Connect Fastmail to Fezola

You need a Fastmail plan that includes IMAP and SMTP (Basic plans do not, according to Fastmail) and an app password.

1. In Fastmail, open Settings, Privacy & Security, then Manage app passwords and access, and create a New app password with the Mail, Contacts & Calendars access type. Copy it.
2. Create a free Fezola account, open Sources and add a mailbox. Choose Other and enter:
   • IMAP: imap.fastmail.com, port 993, TLS.
   • SMTP: smtp.fastmail.com, port 465, TLS (or 587 with STARTTLS).
   • Login: your full Fastmail address. Password: the app password.
3. Give it a short name such as "Fastmail" and click Test the connection. Fezola checks incoming (IMAP) and outgoing (SMTP) mail.
4. Add Fezola to your assistant. In Claude: Customize, Connectors, + Add, Add custom connector, paste https://api.fezola.com/mcp. In ChatGPT (paid plans): Settings, Apps & Connectors, Advanced settings, turn on Developer mode, then create a connector with the same URL.
5. Approve the access, then ask: "What came in on Fastmail and Gmail today that needs an answer?"

Fezola saves the app password encrypted and never shows it again. It is never part of your conversation with the assistant.

What to ask

• "Summarize this week's emails across all my mailboxes and list the ones that need a reply."
• "Find the invoice PDF from the accountant and give me the total."
• "Draft a reply to the last email from the school, from the right address."

Behind the scenes the assistant calls tools such as search_messages, get_attachment and reply_draft. Each result carries its account.

For other hosts that work the same way, see OVH mail in Claude and ChatGPT and the IMAP MCP server guide. Wondering about safety? Is it safe to connect your email to an AI? covers what is stored and how to revoke access. For a broader comparison of options, see best email MCP servers.