Docker Mailserver 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?
Docker Mailserver
Production-ready, config-driven mail server in a container
VS
Nullmailer
Simple relay-only mail transfer agent
| Feature | Docker Mailserver | Nullmailer |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-2.0 |
| Language | Shell | C++ |
| Setup difficulty | Medium | Easy |
| Min. RAM | 2,048 MB | 16 MB |
| Deployment | docker | bare-metal, source |
| GitHub stars | ★ 18,682 | ★ 199 |
| First released | 2015 | 2000 |
| Replaces | Google Workspace, Microsoft 365 | Sendmail |
Why pick each one
Choose Docker Mailserver if…
- Reproducible, version-controllable config
- Lightweight
Frequently asked questions
Is Docker Mailserver or Nullmailer better?
Neither is universally better. Docker Mailserver 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 Docker Mailserver and Nullmailer free and open-source?
Yes. Docker Mailserver is licensed under MIT and Nullmailer under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Docker Mailserver and Nullmailer with Docker?
Docker Mailserver: yes. Nullmailer: check the project docs for container support.