mcp-mail

ChatGPT

Checked against OpenAI’s documentation on 2026-11-02.

ChatGPT connects to remote MCP servers in developer mode (Settings → Apps → Advanced) using OAuth 2.1 with dynamic client registration and PKCE. mcp-mail implements RFC 9207 issuer identification, so ChatGPT uses its stable callback https://chatgpt.com/connector_platform_oauth_redirect, which is in the default ALLOWED_REDIRECT_URIS.

1. Server:

   # .env
   OAUTH=true
   TOKEN_SECRET_FILE=/etc/mcp-mail/token-secret
   CHATGPT_COMPAT=true        # adds read-only `search` and `fetch` for deep research
   

   mcp-mail clients add chatgpt --for chatgpt     # read-only preset, OAuth login printed once
   

2. In ChatGPT: Apps → + → Add custom MCP server, URL https://mail.example.com/mcp, authentication OAuth. Sign in with the login from step 1.
3. After changing presets or tools, press Refresh on the app so ChatGPT re-reads the tool list.

Notes:

• Deep research and company knowledge only use tools named search and fetch; mcp-mail’s versions search Inbox and Sent of every account and return fenced message text.
• Read tools carry readOnlyHint, so ChatGPT runs them without asking; anything else needs your confirmation in the conversation.
• Write tools (drafts, sending) depend on your ChatGPT plan’s developer-mode support.

This site is open source. Improve this page.