Postal vs Sup
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
Sup
Console-based threaded email client
| Feature | Postal | Sup |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-2.0 |
| Language | Ruby | Ruby |
| Setup difficulty | Hard | Medium |
| Min. RAM | 2,048 MB | 128 MB |
| Deployment | docker, bare-metal | binary, source |
| GitHub stars | ★ 16,724 | ★ 970 |
| First released | 2017 | 2007 |
| Replaces | SendGrid, Mailgun, Postmark | Mutt |
Why pick each one
Choose Sup if…
- Released under the GPL-2.0 license
- Written in Ruby
- Tiny footprint — runs in 128 MB RAM
Frequently asked questions
Is Postal or Sup better?
Neither is universally better. Postal has the larger community, while Sup is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Postal and Sup free and open-source?
Yes. Postal is licensed under MIT and Sup under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Postal and Sup with Docker?
Postal: yes. Sup: check the project docs for container support.