# Flow vs Mail-in-a-Box

> Two self-hosted projects, compared on the numbers selfhost.directory tracks live: score, popularity, release cadence and setup effort.

| | Flow | Mail-in-a-Box |
|---|---|---|
| Score | 43/100 | 72/100 ✓ |
| Rank in category | #25 of 30 in Calendar & Contacts | #3 of 16 in Mail Server |
| GitHub stars | 157 | 15 447 ✓ |
| Stars, last 30 days | — | +29 |
| Stable releases, 12 months | 3 | 4 ✓ |
| Latest release | v0.7.0 · 22 Aug 2026 | v77 · 26 Sept 2026 ✓ |
| Setup | Moderate ✓ | Moderate |
| Official Docker image | No | No |
| License | AGPL-3.0 | CC0-1.0 |
| Main language | Dart | Python |

## Which one should you pick?

Mail-in-a-Box scores 72/100 against 43/100 for Flow, so it is the safer default.

Mail-in-a-Box ships more often: 4 stable releases in the past year, against 3 for Flow.

Mail-in-a-Box is growing faster right now (+29 stars in 30 days).

## Details

- [Flow](https://selfhost.directory/project/flow) (markdown: https://selfhost.directory/project/flow.md)
- [Mail-in-a-Box](https://selfhost.directory/project/mail-in-a-box) (markdown: https://selfhost.directory/project/mail-in-a-box.md)

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Source: https://selfhost.directory/compare/flow-vs-mail-in-a-box