Claws Mail vs Stalwart Mail Server
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?
Claws Mail
Lightweight and fast GTK email client
VS
Stalwart Mail Server
Modern all-in-one mail server in a single binary
| Feature | Claws Mail | Stalwart Mail Server |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | GPL-3.0 | AGPL-3.0 |
| Language | C | Rust |
| Setup difficulty | Easy | Medium |
| Min. RAM | 128 MB | 512 MB |
| Deployment | binary, source | docker, binary, bare-metal |
| GitHub stars | ★ 200 | ★ 14,059 |
| First released | 2001 | 2020 |
| Replaces | Microsoft Outlook | Microsoft Exchange, Google Workspace |
Why pick each one
Choose Claws Mail if…
- Released under the GPL-3.0 license
- Easy to set up — beginner-friendly
- Written in C
- Tiny footprint — runs in 128 MB RAM
Choose Stalwart Mail Server if…
- Single modern binary
- Strong security defaults
Frequently asked questions
Is Claws Mail or Stalwart Mail Server better?
Neither is universally better. Stalwart Mail Server has the larger community, while Claws Mail is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are Claws Mail and Stalwart Mail Server free and open-source?
Yes. Claws Mail is licensed under GPL-3.0 and Stalwart Mail Server under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Claws Mail and Stalwart Mail Server with Docker?
Claws Mail: check the project docs for container support. Stalwart Mail Server: yes.