Postfix vs WildDuck
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Postfix | WildDuck |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 75 · Good | 86 · Excellent |
| Category | Mail Servers | Mail Servers |
| License | IPL-1.0 | EUPL-1.2 |
| Language | C | JavaScript |
| Setup difficulty | Hard | Hard |
| Min. RAM | 128 MB | 1,024 MB |
| Deployment | docker, bare-metal, source | docker, bare-metal |
| GitHub stars | ★ 576 | ★ 2,108 |
| First released | 1998 | 2017 |
| Replaces | Microsoft Exchange | Microsoft Exchange, Gmail |
What are Postfix and WildDuck?
Postfix
Postfix is a widely deployed mail transfer agent that routes and delivers email. It is the SMTP backbone of countless self-hosted mail servers thanks to its security and performance.
- High-performance SMTP server
- Strong security architecture
- Flexible routing and policy
- De facto standard MTA
WildDuck
WildDuck is a modern, scalable mail server providing IMAP, POP3, and a full REST API for managing mailboxes. It stores messages in MongoDB and is designed for clustered, highly available deployments.
- IMAP and POP3
- Full REST API
- MongoDB storage
- Designed for scale
Postfix vs WildDuck: key differences
Postfix is written in C, while WildDuck is built with JavaScript. Licensing differs — IPL-1.0 for Postfix versus EUPL-1.2 for WildDuck. Postfix is the lighter option, starting around 128 MB of RAM against 1,024 MB for WildDuck. Postfix is the more established project (first released 1998), while WildDuck arrived in 2017. WildDuck has the considerably larger community, at 2,108 GitHub stars versus 576.
Why pick each one
Choose Postfix if…
- Battle-tested and stable
- Extensive documentation
Watch out for
- Configuration has a steep curve
- Only handles mail transfer
Choose WildDuck if…
- API-driven management
- Horizontally scalable
Watch out for
- Requires MongoDB
- Complex to operate
Frequently asked questions
Is Postfix or WildDuck better?
Neither is universally better. WildDuck has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Postfix and WildDuck free and open-source?
Yes. Postfix is licensed under IPL-1.0 and WildDuck under EUPL-1.2. Both can be self-hosted at no software cost.
Can I run Postfix and WildDuck with Docker?
Postfix: yes. WildDuck: yes.
Which is lighter on resources, Postfix or WildDuck?
Postfix has the smaller minimum footprint at 128 MB of RAM, compared to about 1,024 MB for WildDuck. Real-world usage depends on library size, user count, and enabled features.