Mermoz

Mail for macOS · and for your agents

The mail
must go through.

New mail is sorted before you read it. One key handles a thread. Your whole mailbox lives on your Mac, quiet and instant.

Download for Mac Watch the film

Free & open source · macOS 26 · Gmail · Command line & MCP built in

43 seconds, no sound needed.

Built for a lighter workflow

An inbox that behaves like a flight plan: everything has a status, a destination, and a key to get it there.

Sorted before you read it

Each new email arrives with a suggested status and project. Read it and the suggestion applies, or press y.

One key, done

e done, a archive, ⌫ delete, ⌘Z undo. Select several with ⇧ and move them together.

Flows, not folders

Unread, To do, Waiting, Done. A list or a board, grouped and ordered your way. Your Gmail labels are your projects.

Read what matters

Original, exactly as sent. Or Optimized: the same words without signatures, disclaimers and quoted history. Made once, kept.

Your whole mailbox, instant

Every message lives on your Mac. Search, read and sort offline, with ⌘K for anything else.

Agent first

A first-class command line and MCP server. Your agents search, sort and draft; you approve what leaves.

Agent first

Your agents fly it too.

Everything the app does, the command line does: search, read, sort, draft. Every command speaks --json, and an MCP server plugs Mermoz into Claude, Codex and any agent you run.

  • One command per action, scriptable end to end
  • MCP server built in: mermoz mcp
  • Agents can draft anything. Nothing is sent until you approve it in Mermoz. There is no --yes.
  • Agents report friction with mermoz feedback, so the tool keeps improving
agent@mac — mermoz
$ mermoz list --status todo --json
{ "threads": [{ "number": "M-1287",
  "subject": "Q4 audit — sign by Friday?" }], "total": 1 }
$ mermoz draft reply M-1287 --file reply.md
dft_42  [draft]
$ mermoz send dft_42
error: approval_required: draft dft_42 is waiting for
the user to approve it in Mermoz.  # exit 3
Review · Reply to Marc PetitApprove ✓

The spirit of Mermoz

A promise made in 1930.

In 1930, Jean Mermoz flew the Aéropostale mail across the South Atlantic, from Senegal to Brazil, in a little over twenty hours. Letters that used to take weeks by sea arrived in days.

The Aéropostale pilots had a motto: « Le courrier doit passer », the mail must go through. Mermoz keeps that spirit: mail that moves, light and fast, without the heavy machinery around it.

Mermoz icon

Take off.

Mermoz is free and open source. Sign in with Gmail and your mail is on your Mac in minutes.

Download for Mac

Requires macOS 26 · Source on GitHub