Postal vs OpenSMTPD
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
OpenSMTPD
Secure and simple SMTP server from OpenBSD
| Feature | Postal | OpenSMTPD |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | ISC |
| Language | Ruby | C |
| Setup difficulty | Hard | Medium |
| Min. RAM | 2,048 MB | 32 MB |
| Deployment | docker, bare-metal | bare-metal, source |
| GitHub stars | ★ 16,724 | ★ 579 |
| First released | 2017 | 2013 |
| Replaces | SendGrid, Mailgun, Postmark | Sendmail, Postfix |
Why pick each one
Frequently asked questions
Is Postal or OpenSMTPD better?
Neither is universally better. Postal has the larger community, while OpenSMTPD is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Postal and OpenSMTPD free and open-source?
Yes. Postal is licensed under MIT and OpenSMTPD under ISC. Both can be self-hosted at no software cost.
Can I run Postal and OpenSMTPD with Docker?
Postal: yes. OpenSMTPD: check the project docs for container support.