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Comparison · Comms
mailcow vs Mailu
A side-by-side editorial comparison of mailcow and Mailu — release velocity, themes, recent moves, and the top alternatives to consider.
mailcow vs Mailu: at a glance
What is mailcow?
mailcow's monthly releases are mostly upstream security updates with small UI work
mailcow ships named monthly releases with lettered revisions, and most exist to pull in upstream security fixes for components like SOGo, Nginx, Redis, Unbound and Rspamd. The September release also added an ACL and global switch to stop external alias forwarding, a show-password toggle on login pages, and fixes such as an auth-cache wipe during nginx outages. October moved PHP to an Alpine 3.24 base and brought SOGo 5.12.12, Nginx 1.30.6 and a UI update.
What is Mailu?
Mailu's October: patched PHP for webmail, and a resolver that reports DNS failures
Mailu's 2024.06 branch shipped six pinned releases in October, each tied to a single issue. Three dealt with the resolver: handling the DNSSEC KSK rollover, then making the healthcheck fail on SERVFAIL, re-shipped once. Three were webmail: Roundcube 1.6.20, mitigations for the PHP2Shell CVEs, and then the patched PHP runtime. Late September releases fixed boolean settings that could not be turned off and stale webmail sessions after switching accounts via SSO.
mailcow vs Mailu: editorial side-by-side
mailcow
5.0COMMS
mailcow's monthly releases are mostly upstream security updates with small UI work
◆ Current state
mailcow ships named monthly releases with lettered revisions, and most exist to pull in upstream security fixes for components like SOGo, Nginx, Redis, Unbound and Rspamd. The September release also added an ACL and global switch to stop external alias forwarding, a show-password toggle on login pages, and fixes such as an auth-cache wipe during nginx outages. October moved PHP to an Alpine 3.24 base and brought SOGo 5.12.12, Nginx 1.30.6 and a UI update.
◆ Where it's heading
Keeping a dozen bundled upstreams current is the product, and the cadence is built around that. Feature work arrives in small admin and web UI controls alongside the security updates.
◆ Prediction
Expect a revision of the October release carrying further upstream updates, following the lettered-revision pattern.
Mailu
5.0COMMS
Mailu's October: patched PHP for webmail, and a resolver that reports DNS failures
◆ Current state
Mailu's 2024.06 branch shipped six pinned releases in October, each tied to a single issue. Three dealt with the resolver: handling the DNSSEC KSK rollover, then making the healthcheck fail on SERVFAIL, re-shipped once. Three were webmail: Roundcube 1.6.20, mitigations for the PHP2Shell CVEs, and then the patched PHP runtime. Late September releases fixed boolean settings that could not be turned off and stale webmail sessions after switching accounts via SSO.
◆ Where it's heading
The project remains in one-fix-per-release maintenance on the 2024.06 line, with upstream webmail and PHP security driving much of the cadence. Nothing in the entries points to a new main release.
◆ Prediction
The next releases will most likely follow upstream Roundcube or PHP security fixes, as three of the last six did.
Alternatives to mailcow and Mailu
Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either mailcow or Mailu.
Misskey
Misskey moves to Sentry v11 and keeps shipping security fixes in its monthly releases.
Apprise
Apprise 2 is out: notify() returns a result object, and 2.1 takes the catalog to 170 services.
RSS.com
RSS.com's changelog is back after ten months, with listener voicemail for podcasts.
The Lounge
The Lounge ships steadily but publishes release notes that say nothing.
Slack
Slack lets companies manage Slackbot skills from code and CI, not only by hand
See all mailcow alternatives → · See all Mailu alternatives →
Recent activity from mailcow and Mailu
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 10d agoMailuMailu ships patched PHP for PHP2Shell CVEs
- 11d agoMailuMailu mitigates PHP2Shell webmail CVEs
- 11d agomailcow🎃🐮 Mooctober 2026 | Security Update: PHP 8.2.35, SOGo 5.12.12 & Nginx 1.30.6
- 12d agoMailuMailu 2024.06.65: Roundcube 1.6.20 update
- 18d agoMailu2024.06.64 re-ships the resolver healthcheck fix
- 20d agoMailu2024.06.63 makes the resolver healthcheck catch SERVFAIL
- 21d agoMailu2024.06.62 handles the DNSSEC KSK rollover
- 27d agomailcow2026-09a: Rspamd 4.2.1 and postfix-tlspol bumps
- 1mo agomailcow🍂🐮 Mootember 2026 | Unbound 1.26.1, SOGo 5.12.11 & Redis 7.4.11
- 2mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision B
- 3mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A
- 3mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3
Frequently asked questions
What is the difference between mailcow and Mailu?
They serve adjacent needs but don't currently overlap on shipped themes. mailcow and Mailu are shipping at a similar cadence (velocity 5.0 vs 5.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is mailcow better than Mailu?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. mailcow and Mailu are shipping at a similar cadence (velocity 5.0 vs 5.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.
What are the best alternatives to mailcow?
Top mailcow alternatives in Comms are ranked by recent ship velocity. Browse the "mailcow alternatives" section above for the current picks, or visit /alternatives/mailcow for the full list with editorial commentary on each.
What are the best alternatives to Mailu?
Top Mailu alternatives in Comms are ranked by recent ship velocity. Browse the "Mailu alternatives" section above for the current picks, or visit /alternatives/mailu for the full list with editorial commentary on each.