Cuttlefish vs Mail-in-a-Box
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?
Cuttlefish
Transactional email server with click and open tracking
VS
Mail-in-a-Box
Turn a fresh server into a working mail server
| Feature | Cuttlefish | Mail-in-a-Box |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | AGPL-3.0 | CC0-1.0 |
| Language | Ruby | Python |
| Setup difficulty | Medium | Easy |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, bare-metal, source | bare-metal, one-click |
| GitHub stars | ★ 1,624 | ★ 15,385 |
| First released | 2014 | 2014 |
| Replaces | Mailgun, SendGrid, Postmark | Google Workspace, Microsoft 365 |
Why pick each one
Choose Cuttlefish if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (1.6k GitHub stars)
- Written in Ruby
Frequently asked questions
Is Cuttlefish or Mail-in-a-Box better?
Mail-in-a-Box is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Cuttlefish if its specific feature set fits your needs better.
Are Cuttlefish and Mail-in-a-Box free and open-source?
Yes. Cuttlefish is licensed under AGPL-3.0 and Mail-in-a-Box under CC0-1.0. Both can be self-hosted at no software cost.
Can I run Cuttlefish and Mail-in-a-Box with Docker?
Cuttlefish: yes. Mail-in-a-Box: check the project docs for container support.