Postbode

Rules for your IMAP inbox. Test them with a dry run and undo any delete. Postbode syncs your mail into a local store and runs your rules: move mail into folders, mark it read, or delete transient mail such as sign-in codes and magic links once you no longer need it. Without rules, it leaves your mail alone.

It runs headless as a background service, at login or on a server. On top come a keyboard-driven mail window for reading (postbode gui), a full command line, and an MCP server for agents (see Agents over MCP). Postbode reads and sorts mail; it does not send it. It runs on macOS and Linux.

Quickstart

brew install pataar/tap/postbode    # or cargo, mise, the macOS app or an AppImage: see Install
postbode account add                # asks for host, user and password, then tests the login
postbode sync                       # first sync of every folder
postbode list                       # newest mail in INBOX
postbode gui                        # the mail window
postbode mcp install claude-desktop # let Claude read your inbox and propose rules

Postbode ships with no rules. Add your own to rules.toml next to config.toml, in ~/.config/postbode/ on Linux or ~/Library/Application Support/postbode/ on macOS. For example, this one deletes read sign-in codes after an hour:

[[rules]]
name = "purge sign-in codes"
match.subject = { regex = "(?i)sign.?in|verification code|magic link" }
match.older_than = "1h"
match.seen = true
actions = ["delete"]

postbode rules test       # dry run: what would each rule do?
postbode run              # keep syncing and applying rules in the foreground
postbode service install  # run in the background at login

Deleted mail is kept as .eml for 30 days: postbode trash list and postbode trash restore FILE.

Why not server-side filters?

• Works with any IMAP server, without Sieve or a webmail settings page.
• Rules run on every sync, not once on delivery, so they can act later: an hour after you read a sign-in code, or once a newsletter is a week old.
• rules test shows what every rule would do before it does it, and deleted mail can be restored.
• Agents over MCP get only the scopes you grant, so it stays privacy-friendly: by default they see headers but no message bodies, and propose rules instead of acting on mail.
• Passwords stay in the macOS Keychain or the Secret Service, or come from a command such as pass.

Postbode is licensed under MIT or Apache-2.0, at your option. The mail window’s HTML view includes Stylo, the CSS engine from Servo and Firefox, which is under MPL-2.0.