Dovecot Pigeonhole vs imapfilter

A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
FeatureDovecot Pigeonholeimapfilter
Deploy effortRead-the-docs projectRead-the-docs project
Health score72 · Good57 · Fair
CategoryMail ServersMail Servers
LicenseLGPL-2.1MIT
LanguageCC
Setup difficultyMediumMedium
Min. RAM64 MB32 MB
Deploymentbare-metal, sourcebinary, source
GitHub stars★ 96★ 937
First released20082001
ReplacesGmail filtersGmail filters

What are Dovecot Pigeonhole and imapfilter?

Dovecot Pigeonhole

Dovecot Pigeonhole is the Sieve and ManageSieve implementation that adds server-side mail filtering to a Dovecot installation. It lets users define filtering rules that run as messages are delivered.

  • Server-side Sieve filtering
  • ManageSieve protocol
  • Runs at delivery time
  • Dovecot integration

imapfilter

imapfilter is a mail filtering utility that processes mailboxes directly over IMAP based on rules written in Lua. It runs as a client-side tool and can sort, move, and act on messages.

  • Lua-scripted filtering
  • Works over IMAP
  • Client-side processing
  • Very lightweight

Dovecot Pigeonhole vs imapfilter: key differences

Both projects are written in C. Licensing differs — LGPL-2.1 for Dovecot Pigeonhole versus MIT for imapfilter. Imapfilter is the lighter option, starting around 32 MB of RAM against 64 MB for Dovecot Pigeonhole. Imapfilter is the more established project (first released 2001), while Dovecot Pigeonhole arrived in 2008. Imapfilter has the considerably larger community, at 937 GitHub stars versus 96.

Why pick each one

Choose Dovecot Pigeonhole if…

  • Released under the LGPL-2.1 license
  • Written in C
  • Tiny footprint — runs in 64 MB RAM
Dovecot Pigeonhole details

Choose imapfilter if…

  • Released under the MIT license
  • Written in C
  • Tiny footprint — runs in 32 MB RAM
imapfilter details

Frequently asked questions

Is Dovecot Pigeonhole or imapfilter better?

Neither is universally better. imapfilter has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.

Are Dovecot Pigeonhole and imapfilter free and open-source?

Yes. Dovecot Pigeonhole is licensed under LGPL-2.1 and imapfilter under MIT. Both can be self-hosted at no software cost.

Can I run Dovecot Pigeonhole and imapfilter with Docker?

Dovecot Pigeonhole: check the project docs for container support. imapfilter: check the project docs for container support.

Which is lighter on resources, Dovecot Pigeonhole or imapfilter?

imapfilter has the smaller minimum footprint at 32 MB of RAM, compared to about 64 MB for Dovecot Pigeonhole. Real-world usage depends on library size, user count, and enabled features.

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