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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

FeaturemailcowMailu
SectorCommsComms
Velocity score5.05.0
Sparks · 30d00
Top themesmail-server, self-hosted, security-updates, dockermaintenance-branch, roundcube, cve-patching, self-hosted-mail
Last editorial update1d ago6d ago
WebsiteVisit →Visit →

What is mailcow?

mailcow's release notes are almost entirely upstream security currency.

mailcow ships named seasonal releases with lettered revisions, and nearly every revision exists to pull in an upstream security fix - Redis, ClamAV, SOGo, Rspamd, nginx, unbound, Postfix. Revision B of the Mooly 2026 release updates Redis 7.4.10, ClamAV 1.4.6, and SOGo 5.12.10, adds minor web UI and nginx hardening, and removes a legacy DeltaChat sieve rule. The last release with genuinely new features was the March cut, which added forced 2FA, ACME DNS-01 challenges, and a passwordless autodiscover endpoint.

Read the full mailcow trajectory →

What is Mailu?

Mailu ships one pinned release per issue, and most of them are Roundcube's.

The 2024.06 branch releases on demand: an issue or PR comes in, a pinned version goes out, and the changelog is one or two lines. Four of the six most recent releases are webmail-driven — three Roundcube bumps in this window alone, the latest to 1.6.18 clearing a TLS-configuration warning, an earlier one to 1.6.17 closing two CVEs. The remainder are Mailu's own code: an X-Forwarded-By header fix tied to a published advisory, sieve field escaping that repaired autoreplies and closed an injection path, and two admin-UI form flow corrections.

Read the full Mailu trajectory →

mailcow vs Mailu: editorial side-by-side

M
mailcow
COMMS
5.0

mailcow's release notes are almost entirely upstream security currency.

◆ Current state

mailcow ships named seasonal releases with lettered revisions, and nearly every revision exists to pull in an upstream security fix - Redis, ClamAV, SOGo, Rspamd, nginx, unbound, Postfix. Revision B of the Mooly 2026 release updates Redis 7.4.10, ClamAV 1.4.6, and SOGo 5.12.10, adds minor web UI and nginx hardening, and removes a legacy DeltaChat sieve rule. The last release with genuinely new features was the March cut, which added forced 2FA, ACME DNS-01 challenges, and a passwordless autodiscover endpoint.

◆ Where it's heading

For a self-hosted mail stack that bundles a dozen upstream components, keeping current with their CVEs is the product, and mailcow has organized its release cadence around exactly that. The pattern is consistent: a named release with some feature content every few months, then lettered revisions that are pure security currency plus small web UI escaping and validation fixes. The web interface is where mailcow's own code gets hardened - HTML escaping in quarantine views and sieve editors recurs across several revisions.

◆ Prediction

Expect the next entry to be another lettered revision carrying upstream updates, with the next named release likely bundling whatever feature work has accumulated since March.

M
Mailu
COMMS
5.0

Mailu ships one pinned release per issue, and most of them are Roundcube's.

◆ Current state

The 2024.06 branch releases on demand: an issue or PR comes in, a pinned version goes out, and the changelog is one or two lines. Four of the six most recent releases are webmail-driven — three Roundcube bumps in this window alone, the latest to 1.6.18 clearing a TLS-configuration warning, an earlier one to 1.6.17 closing two CVEs. The remainder are Mailu's own code: an X-Forwarded-By header fix tied to a published advisory, sieve field escaping that repaired autoreplies and closed an injection path, and two admin-UI form flow corrections.

◆ Where it's heading

This is a maintenance branch behaving exactly as a maintenance branch should, and the pinned-version model is the product: operators get upstream security work packaged and tagged without tracking Roundcube themselves. The security items divide cleanly — most arrive from bundled components, a minority from Mailu's own code, and the project patches both on the same cadence. Nothing in this window suggests new capability is being developed on this branch.

◆ Prediction

Expect the next release to follow the same trigger: a Roundcube advisory or a client compatibility report producing a single-line changelog and a new pinned tag. Any feature work would be happening on the main version, which this feed does not cover.

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.

See all mailcow alternatives → · See all Mailu alternatives →

Recent activity from mailcow and Mailu

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 1d agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision B
  2. 6d agoMailuRoundcube 1.6.18 bump clears a TLS-config warning
  3. 20d agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A
  4. 24d agoMailuAutoconfig fix for modern K-9 Mail
  5. 25d agoMailuRoundcube 1.6.17 closes two CVEs
  6. 1mo agoMailuSets X-Forwarded-By in response to a GHSA advisory
  7. 1mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3
  8. 1mo agoMailuAdmin UI keeps form values on failed submit
  9. 1mo agoMailuEscapes sieve fields, fixing autoreplies with special characters
  10. 2mo agomailcowThird May revision: unbound CVE and nginx 1.30.2
  11. 3mo agomailcowSecond May revision: quarantine table HTML escaping
  12. 3mo agomailcowSOGo 5.12.8 covering four upstream security issues

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.