Postal vs Sendmail
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?
| Feature | Postal | Sendmail |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | Sendmail |
| Language | Ruby | C |
| Setup difficulty | Hard | Medium |
| Min. RAM | 2,048 MB | 512 MB |
| Deployment | docker, bare-metal | bare-metal |
| GitHub stars | ★ 16,724 | — |
| First released | 2017 | 2020 |
| Replaces | SendGrid, Mailgun, Postmark | — |
Why pick each one
Choose Sendmail if…
- Released under the Sendmail license
- Written in C
- Lightweight — runs in 512 MB RAM
Frequently asked questions
Is Postal or Sendmail better?
Neither is universally better. Postal has the larger community, while Sendmail is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Postal and Sendmail free and open-source?
Yes. Postal is licensed under MIT and Sendmail under Sendmail. Both can be self-hosted at no software cost.
Can I run Postal and Sendmail with Docker?
Postal: yes. Sendmail: check the project docs for container support.