Mail-in-a-Box vs Sendmail
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?
Mail-in-a-Box
Turn a fresh server into a working mail server
VS
Sendmail
Message transfer agent (MTA)
| Feature | Mail-in-a-Box | Sendmail |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | CC0-1.0 | Sendmail |
| Language | Python | C |
| Setup difficulty | Easy | Medium |
| Min. RAM | 1,024 MB | 512 MB |
| Deployment | bare-metal, one-click | bare-metal |
| GitHub stars | ★ 15,385 | — |
| First released | 2014 | 2020 |
| Replaces | Google Workspace, Microsoft 365 | — |
Why pick each one
Choose Sendmail if…
- Released under the Sendmail license
- Written in C
- Lightweight — runs in 512 MB RAM
Frequently asked questions
Is Mail-in-a-Box or Sendmail better?
Mail-in-a-Box is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Sendmail if its specific feature set fits your needs better.
Are Mail-in-a-Box and Sendmail free and open-source?
Yes. Mail-in-a-Box is licensed under CC0-1.0 and Sendmail under Sendmail. Both can be self-hosted at no software cost.
Can I run Mail-in-a-Box and Sendmail with Docker?
Mail-in-a-Box: check the project docs for container support. Sendmail: check the project docs for container support.