Lumman

Connect your mailboxes and calendars to ChatGPT

Add Multi Mail and Multi Calendar to ChatGPT as custom MCP servers by their addresses, then type @ in a chat and choose one.

The AI apps' own connectors

  • ChatGPT's release notes say its Gmail and Google Calendar plugins connect several Google accounts at once, personal and work in the same conversation. Read on 3 November 2026.
  • Outlook Email and Outlook Calendar, OpenAI's apps for ChatGPT, search messages and read and search calendar events and availability. Read on 3 November 2026.
  • ChatGPT's release notes say its iCloud Mail and iCloud Calendar plugins find emails, catch up on your inbox, check your schedule and update calendar events, on every plan. Read on 3 November 2026.
  • ChatGPT's release notes say that with Gmail or Outlook connected it drafts and sends email from the conversation, sending on the web on Plus, Pro, Business and Enterprise. Read on 3 November 2026.

Connect it

Multi Mail

Gmail, Outlook.com, Hotmail, Microsoft 365, Yahoo, iCloud and other mailboxes, in one connector.

Works fully on ChatGPT Business, Enterprise and Edu.

  1. 1

    Copy the address

  2. 2
    Open ChatGPT plugins

    Press +, choose Add custom MCP server, name it Multi Mail, paste the address, choose OAuth, tick the box and press Create as a plugin.

  3. 3

    Install it, then sign in, add your mailbox and approve on the Lumman page it opens. In a chat, type @ and choose Multi Mail.

Multi Calendar

Your Outlook.com, Microsoft 365, Google, iCloud and other calendars, in one connector.

Works fully on ChatGPT Business, Enterprise and Edu.

  1. 1

    Copy the address

  2. 2
    Open ChatGPT plugins

    Press +, choose Add custom MCP server, name it Multi Calendar, paste the address, choose OAuth, tick the box and press Create as a plugin.

  3. 3

    Install it, then sign in, add your calendar and approve on the Lumman page it opens. In a chat, type @ and choose Multi Calendar.

Reach and limits

  • Search and read every mailbox you add at once, and draft, reply, forward and send from any of them.
  • Archive, bin and file mail, and clean up an inbox by sender, putting back what a clean-up moved.
  • Find free time across every calendar you add, and create, move and cancel events.
  • Share booking links and a booking page, run group polls, and find a time with the people in a circle.

If it refuses

  • OpenAI's help centre says custom MCP servers connect with full MCP on ChatGPT Business, Enterprise and Edu on the web, and with read and fetch permissions on Pro. Read on 3 November 2026.
  • OpenAI's help centre says only admins and owners create a plugin for a custom MCP server in a Business workspace, and in Enterprise and Edu admins can grant selected members permission to create connections to custom MCP servers. Read on 3 November 2026.