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mailcow vs VerneMQ

A side-by-side editorial comparison of mailcow and VerneMQ — release velocity, themes, recent moves, and the top alternatives to consider.

Shared themes:self-hosted

mailcow vs VerneMQ: at a glance

FeaturemailcowVerneMQ
SectorCommsComms
Velocity score5.00.0
Sparks · 30d00
Top themesmail-server, self-hosted, cve-response, xss-hardeningmqtt, clustering, erlang, release-candidates
Last editorial update3d ago2h ago
WebsiteVisit →Visit →

What is mailcow?

Six releases, and every one of them is a security update in some form.

mailcow ships on a monthly tag with lettered revisions, and this window contains no release that isn't security-driven. The May line ran to three revisions in two weeks — an unnamed fix with a CVE identifier withheld until later, SOGo 5.12.8 covering four upstream issues, an unbound CVE, HTML escaping added to the quarantine table, sieve filter editor and queue manager. July brought Rspamd 4.1.0 and later 4.1.4, nginx 1.30.3 and a CVE fix, Postfix moved off bookworm, and a release described only as hardening.

Read the full mailcow trajectory →

What is VerneMQ?

A slow, careful MQTT broker that spent two years landing one breaking storage change.

VerneMQ is in low-cadence maintenance on the 2.1.x line, with releases spaced months apart and a 2.1.3 release candidate open since April. The work is concentrated in the clustering metadata store (vmq_swc), the MQTT session state machine, and WebSocket listener behaviour — the parts operators actually file bugs against. Commercial binaries remain EULA-gated, so the open-source repo is the product surface and the packages are the business.

Read the full VerneMQ trajectory →

mailcow vs VerneMQ: editorial side-by-side

M
mailcow
COMMS
5.0

Six releases, and every one of them is a security update in some form.

◆ Current state

mailcow ships on a monthly tag with lettered revisions, and this window contains no release that isn't security-driven. The May line ran to three revisions in two weeks — an unnamed fix with a CVE identifier withheld until later, SOGo 5.12.8 covering four upstream issues, an unbound CVE, HTML escaping added to the quarantine table, sieve filter editor and queue manager. July brought Rspamd 4.1.0 and later 4.1.4, nginx 1.30.3 and a CVE fix, Postfix moved off bookworm, and a release described only as hardening.

◆ Where it's heading

Two distinct pressures are visible. One is upstream: mailcow bundles Postfix, Rspamd, SOGo, nginx, unbound and Dovecot, so every one of their advisories becomes a mailcow release, and the base image migration from bookworm to trixie is that same maintenance surfacing at the OS layer. The other is the project's own web UI, where output escaping is being retrofitted view by view — quarantine table, sieve editor, queue manager, quarantine overview — which reads as a systematic pass rather than isolated reports. Earlier releases in the feed show where feature work went when it happened: forced 2FA, ACME DNS-01 challenges, and admin controls over EAS and DAV access.

◆ Prediction

Expect the monthly-plus-revisions rhythm to continue with upstream component bumps driving most of it, and the web UI escaping pass to reach the remaining admin views.

V
VerneMQ
COMMS
0.0

A slow, careful MQTT broker that spent two years landing one breaking storage change.

◆ Current state

VerneMQ is in low-cadence maintenance on the 2.1.x line, with releases spaced months apart and a 2.1.3 release candidate open since April. The work is concentrated in the clustering metadata store (vmq_swc), the MQTT session state machine, and WebSocket listener behaviour — the parts operators actually file bugs against. Commercial binaries remain EULA-gated, so the open-source repo is the product surface and the packages are the business.

◆ Where it's heading

The centre of gravity is correctness in clustered deployments, not new protocol capability. Recent releases keep tightening the same three areas — connection accounting under churn, proxy-header handling behind load balancers, and metadata sync for joining nodes — which reads as a broker being hardened for larger clusters rather than broadened. The RC-heavy release pattern (three RCs before 2.1.0, one open for 2.1.3) suggests a small team leaning on community testing before committing.

◆ Prediction

2.1.3 ships as a fix-consolidation release absorbing the remaining open PRs, with the retain-expiry default change carried through. Nothing in these entries points to a new protocol or storage direction after that.

Alternatives to mailcow and VerneMQ

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 VerneMQ.

See all mailcow alternatives → · See all VerneMQ alternatives →

Recent activity from mailcow and VerneMQ

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

  1. 5d agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A
  2. 22d agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3
  3. 2mo agomailcowThird May revision: unbound CVE and nginx 1.30.2
  4. 2mo agomailcowSecond May revision: quarantine table HTML escaping
  5. 2mo agomailcowSOGo 5.12.8 covering four upstream security issues
  6. 2mo agomailcowMay base release: undisclosed CVE plus web UI escaping
  7. 3mo agoVerneMQ2.1.3 RC1: socket-close accounting fix, retain-expiry check off by default
  8. 4mo agoVerneMQ2.1.2 fixes WebSocket connection counts and X-Forwarded-For handling
  9. 10mo agoVerneMQ2.1.1 fixes syslog boot, drops default local listeners
  10. 1y agoVerneMQ2.1.0 lands a breaking on-disk metadata format
  11. 1y agoVerneMQ2.1.0-rc3 makes inter-node connect options configurable
  12. 1y agoVerneMQ2.1.0-rc2: single init_sync flag fix

Frequently asked questions

What is the difference between mailcow and VerneMQ?

Both compete on the same themes — self-hosted — within Comms. mailcow is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is mailcow better than VerneMQ?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. mailcow is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. 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 VerneMQ?

Top VerneMQ alternatives in Comms are ranked by recent ship velocity. Browse the "VerneMQ alternatives" section above for the current picks, or visit /alternatives/vernemq for the full list with editorial commentary on each.