Install imapfilter with Homebrew, apk, apt, dnf, MacPorts, Nix, zypper

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• imapfilter

Project history

IMAPFilter 1.0 was released on May 23, 2004. The project settled into the 2.x line in 2007, and its NEWS file shows steady maintenance around IMAP protocol behavior, mailbox handling, Lua compatibility, TLS/OpenSSL support, and recovery from network failures.

The README describes IMAPFilter as a utility that connects to remote IMAP servers, searches messages, and then deletes, copies, moves, flags, or otherwise processes messages across mailboxes and servers. It documents Lua as both the configuration language and extension language, with manual pages for the command and configuration format.

Adoption history

The project became useful in the niche where users wanted server-side mail triage without running a full mail client or local mail store. Its continued Homebrew formula and release train through the 2.8 series show a long-lived CLI with modest but persistent packaging demand.

The NEWS timeline reflects adaptation to real mail-server drift: TLS 1.1 and 1.2 support in 2013, certificate validation improvements in 2014, XOAUTH2 support in 2015, OpenSSL 3 support in 2022, and UTF-8 IMAP support in 2023.

How it is used

Users write Lua configuration under the documented IMAPFilter config path, then run the CLI to search remote mailboxes and apply actions. Because credentials can live in the same Lua config, the tool is often treated like a personal automation script with careful file permissions.

Typical package-nerd usage is cron-style mailbox hygiene: delete or move old mail, copy messages between accounts, flag matching messages, or use Lua extensions when ordinary IMAP search expressions are not expressive enough.

Why package nerds care

IMAPFilter is a classic example of a small C/Unix utility made powerful by embedding a scripting language. For package people, it sits in the same mental drawer as fetchmail, procmail, and notmuch-adjacent mail tools: compact, automatable, and opinionated about text configuration.

Its history is also a reminder that email automation packages age by tracking servers, TLS stacks, authentication methods, and language runtimes. The interesting maintenance work is less feature splash and more staying compatible with IMAP providers and Lua/OpenSSL releases.

Timeline

• 2004: IMAPFilter 1.0 is released.
• 2007: IMAPFilter 2.0 introduces the long-running 2.x series.
• 2012: IMAPFilter 2.5 adds session recovery and Lua 5.2 compatibility while making OpenSSL mandatory.
• 2015: IMAPFilter 2.6 adds Lua 5.3 compatibility and later XOAUTH2 support.
• 2020: IMAPFilter 2.7 adds Lua 5.4 and PCRE2 compatibility.
• 2023: IMAPFilter 2.8 adds a new recovery mechanism; 2.8.2 adds UTF-8 IMAP support.
• 2026: IMAPFilter 2.8.5 re-adds an OAuth2 example in the sample extension file.

Related projects

• Lua is central to IMAPFilter's configuration and extension model.
• OpenSSL and PCRE2 are key build-time dependencies named by the project README.
• Other mail automation tools such as procmail, fetchmail, offlineimap, mbsync, and notmuch occupy adjacent packaging territory, though IMAPFilter focuses on remote IMAP mailbox processing.

Sources

• https://api.github.com/repos/lefcha/imapfilter
• https://formulae.brew.sh/api/formula/imapfilter.json
• https://github.com/lefcha/imapfilter
• https://raw.githubusercontent.com/lefcha/imapfilter/master/NEWS
• https://raw.githubusercontent.com/lefcha/imapfilter/master/README