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Comparison · Comms

mailcow vs Rocket.Chat

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

Shared themes:self-hosted

mailcow vs Rocket.Chat: at a glance

FeaturemailcowRocket.Chat
SectorCommsComms
Velocity score5.06.3
Sparks · 30d00
Top themesmail-server, self-hosted, security-updates, breaking-changesteam-chat, licensing, self-hosted, performance
Last editorial update8d ago4d ago
WebsiteVisit →Visit →

What is mailcow?

mailcow's November release patches an admin RCE and reworks sync jobs.

mailcow ships named monthly releases with lettered revisions, mostly to pull in upstream security fixes for SOGo, Nginx, Redis, Unbound and Rspamd. The November release goes further: it fixes a remote code execution flaw reachable by admins and domain admins, adds mailbox groups, and reworks imapsync so sync jobs reference a separate source. It also caps request bodies at 64 MB, which breaks large SOGo and ActiveSync mail unless NGINX_MAX_BODY_SIZE is raised.

Read the full mailcow trajectory →

What is Rocket.Chat?

Rocket.Chat 9.0 reaches rc.8 with a migration fix as candidates shrink to single patches.

The 9.0 candidate line opened on 27 October with a licensing change: LDAP, SAML and Custom OAuth now require a premium plan. Since rc.4 the candidates have been fixes, and rc.8 on 7 November carries a single one: servers that started during another server's database migration no longer keep stale settings until restart. On 6 November 8.9.1 LTS backported the 9.0 load fixes plus a security hotfix.

Read the full Rocket.Chat trajectory →

mailcow vs Rocket.Chat: editorial side-by-side

M
mailcow
COMMS
5.0

mailcow's November release patches an admin RCE and reworks sync jobs.

◆ Current state

mailcow ships named monthly releases with lettered revisions, mostly to pull in upstream security fixes for SOGo, Nginx, Redis, Unbound and Rspamd. The November release goes further: it fixes a remote code execution flaw reachable by admins and domain admins, adds mailbox groups, and reworks imapsync so sync jobs reference a separate source. It also caps request bodies at 64 MB, which breaks large SOGo and ActiveSync mail unless NGINX_MAX_BODY_SIZE is raised.

◆ Where it's heading

The monthly security cadence holds, but recent releases carry more of mailcow's own features and API changes alongside the upstream bumps. Breaking changes now come with explicit migration steps, which suggests the API is being cleaned up for integrators.

◆ Prediction

Expect the promised RCE advisory details next week and a lettered revision within weeks to address fallout from the sync job API and body-size changes.

Rocket.Chat logo6.3

Rocket.Chat 9.0 reaches rc.8 with a migration fix as candidates shrink to single patches.

◆ Current state

The 9.0 candidate line opened on 27 October with a licensing change: LDAP, SAML and Custom OAuth now require a premium plan. Since rc.4 the candidates have been fixes, and rc.8 on 7 November carries a single one: servers that started during another server's database migration no longer keep stale settings until restart. On 6 November 8.9.1 LTS backported the 9.0 load fixes plus a security hotfix.

◆ Where it's heading

9.0 is in stabilization: each candidate is smaller than the last, and the load fixes are being carried to the LTS line rather than held for the major. Native LiveKit video is being promoted step by step, from alpha to beta and now as the named default provider option.

◆ Prediction

With rc.7 down to a handful of fixes, 9.0.0 GA is the next likely release, followed by further 8.9.x LTS patches carrying the same fixes.

Alternatives to mailcow and Rocket.Chat

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 Rocket.Chat.

See all mailcow alternatives → · See all Rocket.Chat alternatives →

Recent activity from mailcow and Rocket.Chat

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

  1. 7d agoRocket.Chat9.0 rc.8: settings refresh after concurrent migrations
  2. 8d agoRocket.Chat8.9.1 LTS: load fixes from 9.0 plus a security hotfix
  3. 8d agoRocket.Chat9.0 rc.7: client memory leak fixed, LiveKit video moves to beta
  4. 9d agomailcowMoovember 2026: admin RCE fix, mailbox groups, imapsync rework
  5. 9d agoRocket.Chat9.0 rc.6: Matrix federation auth header fix
  6. 9d agoRocket.Chat9.0 rc.5: removed-license features shut off, OAuth codes redacted
  7. 10d agoRocket.Chat9.0 rc.4: notifications, presence and startup fixed under load
  8. 23d agomailcow🎃🐮 Mooctober 2026 | Security Update: PHP 8.2.35, SOGo 5.12.12 & Nginx 1.30.6
  9. 1mo agomailcow2026-09a: Rspamd 4.2.1 and postfix-tlspol bumps
  10. 1mo agomailcow🍂🐮 Mootember 2026 | Unbound 1.26.1, SOGo 5.12.11 & Redis 7.4.11
  11. 2mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision B
  12. 3mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A

Frequently asked questions

What is the difference between mailcow and Rocket.Chat?

Both compete on the same themes — self-hosted — within Comms. Rocket.Chat is currently shipping more aggressively (velocity 6.3 vs 5.0), 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 Rocket.Chat?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Rocket.Chat is currently shipping more aggressively (velocity 6.3 vs 5.0), 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 Rocket.Chat?

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