SimpleLogin 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?
SimpleLogin
Open source email alias solution to protect your email address
VS
smtp4dev
Fake SMTP server for development email testing
| Feature | SimpleLogin | smtp4dev |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-3.0 |
| Language | Python | C# |
| Setup difficulty | Medium | Easy |
| Min. RAM | 512 MB | 128 MB |
| Deployment | docker | docker, binary |
| GitHub stars | ★ 6,896 | ★ 3,941 |
| First released | 2026 | 2015 |
| Replaces | — | Mailtrap |
Why pick each one
Choose SimpleLogin if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Mature project with 6.9k GitHub stars
- Written in Python
Frequently asked questions
Is SimpleLogin or smtp4dev better?
Neither is universally better. SimpleLogin 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 SimpleLogin and smtp4dev free and open-source?
Yes. SimpleLogin is licensed under MIT and smtp4dev under GPL-3.0. Both can be self-hosted at no software cost.
Can I run SimpleLogin and smtp4dev with Docker?
SimpleLogin: yes. smtp4dev: yes.