Mox 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?
Mox
Modern, secure all-in-one mail server
VS
smtp4dev
Fake SMTP server for development email testing
| Feature | Mox | smtp4dev |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-3.0 |
| Language | Go | C# |
| Setup difficulty | Easy | Easy |
| Min. RAM | 256 MB | 128 MB |
| Deployment | docker, binary, source | docker, binary |
| GitHub stars | ★ 5,771 | ★ 3,941 |
| First released | 2023 | 2015 |
| Replaces | Google Workspace, Microsoft 365 | Mailtrap |
Why pick each one
Frequently asked questions
Is Mox or smtp4dev better?
Neither is universally better. Mox has the larger community; both share a easy setup difficulty, so the decision comes down to features and licensing.
Are Mox and smtp4dev free and open-source?
Yes. Mox is licensed under MIT and smtp4dev under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Mox and smtp4dev with Docker?
Mox: yes. smtp4dev: yes.