Compare / Mailcow vs Mail-in-a-Box
Mailcow vs Mail-in-a-Box
Pick Mailcow if you want the published Outlook/Superhuman stack (docker-compose groupware). Pick Mail-in-a-Box if you want that one-box installer on a machine you are willing to let it own.
Facts checked 24 Oct 2026. License, language, and GitHub activity come from the catalog or the project's own repo. "Not in the catalog row" means the public catalog dump does not store that number.
Mailcow in the catalog Mail-in-a-Box in the catalog Start on Railway
How they compare
| Mailcow | Mail-in-a-Box | |
|---|---|---|
| License | GPL-3.0 (catalog) source | CC0-1.0 (catalog) source |
| Language | JavaScript (catalog) | Python (catalog) |
| GitHub activity | 13,685 stars in the catalog source | 15,449 stars in the catalog source |
| Self-host | Published as /stacks/mailcow-mailbox. docker-compose groupware. | Same stack. One-box installer that wants the whole machine. |
| Best for | The published Outlook replacement. | A dedicated box you let the installer own. |
Self-hosting and resource needs
Both sit on /stacks/mailcow-mailbox. Mailcow is mailcow/mailcow-dockerized. Mail-in-a-Box is mail-in-a-box/mailinabox and expects to own the box. Stalwart is the one-binary sibling — /compare/stalwart-vs-mailcow. Thunderbird stays on the laptop. You still need a public IP, MX, and rDNS. Neither has a one-click c17 Railway template.
FAQ
- Outlook or Superhuman?
- Same published mailbox — /replace/outlook and /replace/superhuman. The client AI stays behind. Thunderbird stays on the laptop.
- Where is Stalwart?
- /compare/stalwart-vs-mailcow. Skip SELv2 if you want OSS-only.
- Are these free?
- Mailcow is GPL-3.0. Mail-in-a-Box is CC0-1.0. You pay the VPS and IP reputation.
- How do I deploy Mailcow?
- Open /stacks/mailcow-mailbox. A VPS with MX and rDNS is the honest path. Create one mailbox.
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