imapfilter vs Sieve Editor
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | imapfilter | Sieve Editor |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 57 · Fair | 60 · Good |
| Category | Mail Servers | Mail Servers |
| License | MIT | AGPL-3.0 |
| Language | C | JavaScript |
| Setup difficulty | Medium | Easy |
| Min. RAM | 32 MB | 128 MB |
| Deployment | binary, source | binary, source |
| GitHub stars | ★ 937 | ★ 892 |
| First released | 2001 | 2012 |
| Replaces | Gmail filters | Gmail filters |
What are imapfilter and Sieve Editor?
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
Sieve Editor
The Sieve Editor is a cross-platform graphical application for creating and editing Sieve mail filters on any ManageSieve-capable server. It lets users of self-hosted mail servers manage server-side filtering without editing scripts by hand.
- Graphical Sieve filter editor
- Works with ManageSieve servers
- Cross-platform desktop app
imapfilter vs Sieve Editor: key differences
Imapfilter is written in C, while Sieve Editor is built with JavaScript. Licensing differs — MIT for imapfilter versus AGPL-3.0 for Sieve Editor. Imapfilter is the lighter option, starting around 32 MB of RAM against 128 MB for Sieve Editor. Imapfilter is the more established project (first released 2001), while Sieve Editor arrived in 2012.
Why pick each one
Choose imapfilter if…
- Released under the MIT license
- Written in C
- Tiny footprint — runs in 32 MB RAM
Choose Sieve Editor if…
- Released under the AGPL-3.0 license
- Easy to set up — beginner-friendly
- Written in JavaScript
- Tiny footprint — runs in 128 MB RAM
Frequently asked questions
Is imapfilter or Sieve Editor better?
Neither is universally better. imapfilter has the larger community, while Sieve Editor is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are imapfilter and Sieve Editor free and open-source?
Yes. imapfilter is licensed under MIT and Sieve Editor under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run imapfilter and Sieve Editor with Docker?
imapfilter: check the project docs for container support. Sieve Editor: check the project docs for container support.
Which is lighter on resources, imapfilter or Sieve Editor?
imapfilter has the smaller minimum footprint at 32 MB of RAM, compared to about 128 MB for Sieve Editor. Real-world usage depends on library size, user count, and enabled features.