imapsync 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?
imapsync
Synchronization and migration tool between IMAP accounts
VS
smtp4dev
Fake SMTP server for development email testing
| Feature | imapsync | smtp4dev |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | GPL-3.0 | GPL-3.0 |
| Language | Shell | C# |
| Setup difficulty | Medium | Easy |
| Min. RAM | 64 MB | 128 MB |
| Deployment | binary, source | docker, binary |
| GitHub stars | ★ 4,118 | ★ 3,941 |
| First released | 2003 | 2015 |
| Replaces | IMAP migration services | Mailtrap |
Why pick each one
Choose imapsync if…
- Released under the GPL-3.0 license
- Active community (4.1k GitHub stars)
- Written in Shell
- Tiny footprint — runs in 64 MB RAM
Frequently asked questions
Is imapsync or smtp4dev better?
Neither is universally better. imapsync 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 imapsync and smtp4dev free and open-source?
Yes. imapsync is licensed under GPL-3.0 and smtp4dev under GPL-3.0. Both can be self-hosted at no software cost.
Can I run imapsync and smtp4dev with Docker?
imapsync: check the project docs for container support. smtp4dev: yes.