Postal vs Nullmailer
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
Nullmailer
Simple relay-only mail transfer agent
| Feature | Postal | Nullmailer |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-2.0 |
| Language | Ruby | C++ |
| Setup difficulty | Hard | Easy |
| Min. RAM | 2,048 MB | 16 MB |
| Deployment | docker, bare-metal | bare-metal, source |
| GitHub stars | ★ 16,724 | ★ 199 |
| First released | 2017 | 2000 |
| Replaces | SendGrid, Mailgun, Postmark | Sendmail |
Why pick each one
Frequently asked questions
Is Postal or Nullmailer better?
Neither is universally better. Postal has the larger community, while Nullmailer is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are Postal and Nullmailer free and open-source?
Yes. Postal is licensed under MIT and Nullmailer under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Postal and Nullmailer with Docker?
Postal: yes. Nullmailer: check the project docs for container support.