RainLoop 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?
RainLoop
Simple, modern and fast web-based email client
VS
Stalwart Mail Server
Modern all-in-one mail server in a single binary
| Feature | RainLoop | Stalwart Mail Server |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | AGPL-3.0 | AGPL-3.0 |
| Language | PHP | Rust |
| Setup difficulty | Easy | Medium |
| Min. RAM | 128 MB | 512 MB |
| Deployment | docker, bare-metal, source | docker, binary, bare-metal |
| GitHub stars | ★ 4,120 | ★ 14,059 |
| First released | 2013 | 2020 |
| Replaces | Gmail, Outlook Web | Microsoft Exchange, Google Workspace |
Why pick each one
Choose RainLoop if…
- Released under the AGPL-3.0 license
- Easy to set up — beginner-friendly
- First-class Docker support for quick deployment
- Active community (4.1k GitHub stars)
Choose Stalwart Mail Server if…
- Single modern binary
- Strong security defaults
Frequently asked questions
Is RainLoop or Stalwart Mail Server better?
Neither is universally better. Stalwart Mail Server has the larger community, while RainLoop is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are RainLoop and Stalwart Mail Server free and open-source?
Yes. RainLoop is licensed under AGPL-3.0 and Stalwart Mail Server under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run RainLoop and Stalwart Mail Server with Docker?
RainLoop: yes. Stalwart Mail Server: yes.