Mailu vs smtp4dev
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?
Mailu
Simple yet full-featured Docker mail server
VS
smtp4dev
Fake SMTP server for development email testing
| Feature | Mailu | smtp4dev |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-3.0 |
| Language | Python | C# |
| Setup difficulty | Medium | Easy |
| Min. RAM | 2,048 MB | 128 MB |
| Deployment | docker, kubernetes | docker, binary |
| GitHub stars | ★ 7,443 | ★ 3,941 |
| First released | 2016 | 2015 |
| Replaces | Google Workspace, Microsoft 365 | Mailtrap |
Why pick each one
Frequently asked questions
Is Mailu or smtp4dev better?
Neither is universally better. Mailu has the larger community, while smtp4dev is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are Mailu and smtp4dev free and open-source?
Yes. Mailu is licensed under MIT and smtp4dev under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Mailu and smtp4dev with Docker?
Mailu: yes. smtp4dev: yes.