mail-muncher MCP server

mail-muncher

Give a program its own read-only mailbox, filtered down to exactly the mail it asked for, delivered as files on disk.

mail-muncher pulls messages from a mail provider, evaluates each one against ordered rules, and writes the matches to a directory — byte-faithful .eml, and optionally a markdown rendering with the headers as YAML frontmatter, the body as text, and attachments extracted alongside. A rule can take its filter input from a plain text file that some other program owns, which mail-muncher re-reads at the start of every cycle. That other program changes one line in that file, and the very next cycle delivers different mail — no config edit, no restart, no redeploy.

It reads from any IMAP mailbox — Gmail, Fastmail, iCloud, Proton Bridge, a work account, your own server — or from Gmail's API with a read-only OAuth scope. It runs one-shot for cron, or as a polling daemon, or as a stdio MCP server an agent can query directly. Every mode emits the same machine-readable manifest of what it did, and no mode ever writes to your mailbox.

Two ways to connect a mailbox

Pick one before you install anything. Both are supported, and everything downstream — rules, formats, filenames, the archive layout, the MCP tools — is identical either way.

The ~2 min / ~10 min / 7 days above are the same numbers mail-muncher init and the unconfigured-run guidance print, because they are the numbers that decide this.

The read-only guarantee is real on both paths, but it is not the same guarantee, and flattening the two would be dishonest.

Shortened. The full README is on GitHub.