Postal vs RainLoop
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?
Postal
Complete mail delivery platform for outgoing email
VS
RainLoop
Simple, modern and fast web-based email client
| Feature | Postal | RainLoop |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | AGPL-3.0 |
| Language | Ruby | PHP |
| Setup difficulty | Hard | Easy |
| Min. RAM | 2,048 MB | 128 MB |
| Deployment | docker, bare-metal | docker, bare-metal, source |
| GitHub stars | ★ 16,724 | ★ 4,120 |
| First released | 2017 | 2013 |
| Replaces | SendGrid, Mailgun, Postmark | Gmail, Outlook Web |
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)
Frequently asked questions
Is Postal or RainLoop better?
Neither is universally better. Postal 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 Postal and RainLoop free and open-source?
Yes. Postal is licensed under MIT and RainLoop under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Postal and RainLoop with Docker?
Postal: yes. RainLoop: yes.