Compare / Stalwart vs Mailcow
Stalwart vs Mailcow
Pick Stalwart if you want one Rust binary and will skip SELv2. Pick Mailcow if you want the published Outlook/Superhuman path (docker-compose groupware).
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.
Stalwart in the catalog Mailcow in the catalog Start on Railway
How they compare
| Stalwart | Mailcow | |
|---|---|---|
| License | Other (catalog; skip SELv2 for AGPL-3.0 core) source | GPL-3.0 (catalog) source |
| Language | Rust (catalog) | JavaScript (catalog) |
| GitHub activity | 15,283 stars in the catalog source | 13,685 stars in the catalog source |
| Self-host | One binary plus a volume. Also on /stacks/stalwart-mail. | Published as /stacks/mailcow-mailbox. docker-compose. |
| Best for | A single Rust mail server if you skip SELv2. | The published Outlook replacement. |
Self-hosting and resource needs
Mailcow is the published lander — /stacks/mailcow-mailbox. Stalwart is also named there and already on /stacks/stalwart-mail for the Gmail/Workers path. GitHub's license field on stalwartlabs/stalwart is unset (catalog Other); the project documents dual AGPL-3.0 / SELv2 — skip SELv2 if you want OSS-only. Mail-in-a-Box is the installer sibling — /compare/mailcow-vs-mail-in-a-box.
FAQ
- What is SELv2?
- Stalwart dual-licenses AGPL-3.0 and SELv2. Skip SELv2 if you want OSS-only. GitHub's license field is unset.
- Is this Gmail?
- Gmail stays on /replace/gmail. This pair is still the mailbox. Mailcow is the Outlook lander.
- Are these free?
- Stalwart core is AGPL-3.0 if you skip SELv2. Mailcow is GPL-3.0. You pay the VPS and IP reputation.
- How do I deploy Stalwart?
- Follow stalw.art self-host docs. The published Outlook path remains /stacks/mailcow-mailbox.
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