Docker Mailserver vs OpenDKIM
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
OpenDKIM
DKIM signing and verification filter for mail servers
| Feature | Docker Mailserver | OpenDKIM |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | BSD-3-Clause |
| Language | Shell | C |
| Setup difficulty | Medium | Medium |
| Min. RAM | 2,048 MB | 64 MB |
| Deployment | docker | bare-metal, source |
| GitHub stars | ★ 18,682 | ★ 117 |
| First released | 2015 | 2009 |
| Replaces | Google Workspace, Microsoft 365 | Proprietary email security gateways |
Why pick each one
Choose Docker Mailserver if…
- Reproducible, version-controllable config
- Lightweight
Choose OpenDKIM if…
- Released under the BSD-3-Clause license
- Written in C
- Tiny footprint — runs in 64 MB RAM
Frequently asked questions
Is Docker Mailserver or OpenDKIM 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 Docker Mailserver and OpenDKIM free and open-source?
Yes. Docker Mailserver is licensed under MIT and OpenDKIM under BSD-3-Clause. Both can be self-hosted at no software cost.
Can I run Docker Mailserver and OpenDKIM with Docker?
Docker Mailserver: yes. OpenDKIM: check the project docs for container support.