Self-hosting M365 gray-mail filtering with Mail-Triage

Gray mail is the stuff that technically isn’t spam but absolutely isn’t worth your attention either: receipts, shipping updates, the fourth newsletter you forgot you subscribed to. Microsoft 365’s built-in tools never quite drew the line where I wanted it.

One config file, many mailboxes

Mail-Triage runs as a self-hosted service and reads a single plain-text config. Each mailbox gets its rules, and every action lands in an audit log so I can see exactly what moved and why.

mailboxes:
  - user: tyler@example.com
    rules:
      - match: "from:newsletters"
        action: archive
      - match: "subject:receipt"
        action: label: Receipts

It’s deliberately boring. It does one thing, it tells you what it did, and it leaves the data on hardware I control.