Apache James vs Exim
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Apache James | Exim |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 78 · Good | 15 · At risk |
| Status | Actively maintained | Archived |
| Category | Mail Servers | Mail Servers |
| License | Apache-2.0 | GPL-2.0 |
| Language | Java | C |
| Setup difficulty | Hard | Hard |
| Min. RAM | 2,048 MB | 64 MB |
| Deployment | docker, source | bare-metal, source |
| GitHub stars | ★ 1,044 | ★ 785 |
| First released | 2003 | 1995 |
| Replaces | Microsoft Exchange | Microsoft Exchange |
What are Apache James and Exim?
Apache James
Apache James is a complete enterprise mail server and SMTP, IMAP, and POP3 platform from the Apache Foundation. It can be fully self-hosted and extended with custom mailets for processing mail.
- Enterprise mail server platform
- SMTP, IMAP, and POP3 support
- Extensible with custom mailets
Exim
Exim is a highly configurable mail transfer agent used to route and deliver email on Unix systems. It powers a large share of the internet's mail servers and supports extensive policy and ACL controls.
- Powerful routing rules
- ACL-based policy
- Wide platform support
- Mature codebase
Apache James vs Exim: key differences
The biggest difference is maintenance: Exim's repository is archived and no longer developed, while Apache James is actively maintained. Apache James is written in Java, while Exim is built with C. Licensing differs — Apache-2.0 for Apache James versus GPL-2.0 for Exim. Exim is the lighter option, starting around 64 MB of RAM against 2,048 MB for Apache James. Exim is the more established project (first released 1995), while Apache James arrived in 2003. Apache James lists first-class Docker deployment; Exim does not.
Why pick each one
Choose Apache James if…
- Released under the Apache-2.0 license
- First-class Docker support for quick deployment
- Active community (1k GitHub stars)
- Written in Java
Choose Exim if…
- Extremely flexible
- Proven at scale
Watch out for
- Complex configuration
- Easy to misconfigure
Frequently asked questions
Is Apache James or Exim better?
Neither is universally better. Apache James has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Apache James and Exim free and open-source?
Yes. Apache James is licensed under Apache-2.0 and Exim under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Apache James and Exim with Docker?
Apache James: yes. Exim: check the project docs for container support.
Which is lighter on resources, Apache James or Exim?
Exim has the smaller minimum footprint at 64 MB of RAM, compared to about 2,048 MB for Apache James. Real-world usage depends on library size, user count, and enabled features.