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mailcow vs Stalwart

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

Shared themes:self-hosted

mailcow vs Stalwart: at a glance

FeaturemailcowStalwart
SectorCommsComms
Velocity score5.06.3
Sparks · 30d01
Top themesmail-server, self-hosted, security-updates, dockeremail-server, scim, jmap, enterprise-provisioning
Last editorial update29d ago8d 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 Stalwart?

Stalwart adds full SCIM v2 provisioning and 24-language calendar support as its standards coverage extends further than most commercial mail servers.

Stalwart is maintaining a weekly-or-faster release cadence, with alternating feature releases and dense bug-fix releases. The v0.16.20 release landed full SCIM v2 (Enterprise) including cursor-based pagination and the IPSIE lifecycle profile, conference links in calendar invites, and 24 new calendar interface translations. Below the feature line, the project is steadily closing correctness gaps across JMAP, CalDAV, IMAP, and MTA — many of them edge-case RFC compliance issues.

Read the full Stalwart trajectory →

mailcow vs Stalwart: 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.

S6.3

Stalwart adds full SCIM v2 provisioning and 24-language calendar support as its standards coverage extends further than most commercial mail servers.

◆ Current state

Stalwart is maintaining a weekly-or-faster release cadence, with alternating feature releases and dense bug-fix releases. The v0.16.20 release landed full SCIM v2 (Enterprise) including cursor-based pagination and the IPSIE lifecycle profile, conference links in calendar invites, and 24 new calendar interface translations. Below the feature line, the project is steadily closing correctness gaps across JMAP, CalDAV, IMAP, and MTA — many of them edge-case RFC compliance issues.

◆ Where it's heading

Stalwart is building toward parity with commercial enterprise mail servers on identity federation and provisioning (SCIM v2, VAPID for web push, DMARCbis/DKIM2 already landed). The pace of RFC implementation is unusually aggressive for an open-source project; the combination of JMAP, CalDAV, IMAP UIDONLY/UIDBATCHES, and SCIM v2 positions it as a viable self-hosted alternative for organizations that need standards compliance without vendor lock-in.

◆ Prediction

WebAuthn/passkey-based authentication and improved multi-tenant administration tooling are the most likely next capability additions, given the current trajectory toward enterprise identity management.

Alternatives to mailcow and Stalwart

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 Stalwart.

See all mailcow alternatives → · See all Stalwart alternatives →

Recent activity from mailcow and Stalwart

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

  1. 10d agoStalwartv0.16.21
  2. 17d agoStalwartv0.16.20
  3. 22d agoStalwartv0.16.19
  4. 29d agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision B
  5. 29d agoStalwartv0.16.18
  6. 1mo agoStalwartv0.16.17
  7. 1mo agoStalwartv0.16.16
  8. 1mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A
  9. 2mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3
  10. 3mo agomailcowThird May revision: unbound CVE and nginx 1.30.2
  11. 3mo agomailcowSecond May revision: quarantine table HTML escaping
  12. 4mo agomailcowSOGo 5.12.8 covering four upstream security issues

Frequently asked questions

What is the difference between mailcow and Stalwart?

Both compete on the same themes — self-hosted — within Comms. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 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 Stalwart?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 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 Stalwart?

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