DKIMpy Milter vs Docker Mailserver
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?
DKIMpy Milter
DKIM signing and verification milter for mail servers
VS
Docker Mailserver
Production-ready, config-driven mail server in a container
| Feature | DKIMpy Milter | Docker Mailserver |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | GPL-2.0 | MIT |
| Language | Python | Shell |
| Setup difficulty | Medium | Medium |
| Min. RAM | 64 MB | 2,048 MB |
| Deployment | bare-metal, source | docker |
| GitHub stars | ★ 20 | ★ 18,682 |
| First released | 2018 | 2015 |
| Replaces | Hosted email authentication | Google Workspace, Microsoft 365 |
Why pick each one
Choose DKIMpy Milter if…
- Released under the GPL-2.0 license
- Written in Python
- Tiny footprint — runs in 64 MB RAM
Choose Docker Mailserver if…
- Reproducible, version-controllable config
- Lightweight
Frequently asked questions
Is DKIMpy Milter or Docker Mailserver better?
Neither is universally better. Docker Mailserver has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are DKIMpy Milter and Docker Mailserver free and open-source?
Yes. DKIMpy Milter is licensed under GPL-2.0 and Docker Mailserver under MIT. Both can be self-hosted at no software cost.
Can I run DKIMpy Milter and Docker Mailserver with Docker?
DKIMpy Milter: check the project docs for container support. Docker Mailserver: yes.