Postal vs OpenDMARC
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
OpenDMARC
DMARC policy enforcement filter for mail servers
| Feature | Postal | OpenDMARC |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | BSD-3-Clause |
| Language | Ruby | C |
| Setup difficulty | Hard | Medium |
| Min. RAM | 2,048 MB | 64 MB |
| Deployment | docker, bare-metal | bare-metal, source |
| GitHub stars | ★ 16,724 | ★ 137 |
| First released | 2017 | 2012 |
| Replaces | SendGrid, Mailgun, Postmark | Proprietary DMARC services |
Why pick each one
Choose OpenDMARC if…
- Released under the BSD-3-Clause license
- Written in C
- Tiny footprint — runs in 64 MB RAM
Frequently asked questions
Is Postal or OpenDMARC better?
Neither is universally better. Postal has the larger community, while OpenDMARC is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Postal and OpenDMARC free and open-source?
Yes. Postal is licensed under MIT and OpenDMARC under BSD-3-Clause. Both can be self-hosted at no software cost.
Can I run Postal and OpenDMARC with Docker?
Postal: yes. OpenDMARC: check the project docs for container support.