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Comparison · Comms
mailcow vs Rspamd
A side-by-side editorial comparison of mailcow and Rspamd — release velocity, themes, recent moves, and the top alternatives to consider.
mailcow vs Rspamd: 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 Rspamd?
Rspamd 4.2 hardens its parsers and ships memory-safety fixes three releases running.
The 4.2 line opened in September with a public suffix lookup replacing the old TLD tables, attachment content extraction for SVG, OOXML and DOCX, and one scheduler over the symbol dependency graph. 4.2.1 fixed critical memory-safety bugs including an HTTP heap overflow. 4.2.2 added wallet-address detection across twelve named currencies and changed MIME digests. 4.2.3 stopped trusting ARC forwarders whose seal fails and merged duplicate RBL queries, so a rule scores once per matched value.
mailcow vs Rspamd: 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.
Rspamd
5.0COMMS
Rspamd 4.2 hardens its parsers and ships memory-safety fixes three releases running.
◆ Current state
The 4.2 line opened in September with a public suffix lookup replacing the old TLD tables, attachment content extraction for SVG, OOXML and DOCX, and one scheduler over the symbol dependency graph. 4.2.1 fixed critical memory-safety bugs including an HTTP heap overflow. 4.2.2 added wallet-address detection across twelve named currencies and changed MIME digests. 4.2.3 stopped trusting ARC forwarders whose seal fails and merged duplicate RBL queries, so a rule scores once per matched value.
◆ Where it's heading
The input-hardening walk from 4.1.x has become line-wide policy: limits on untrusted UCL, bounded PDF and decompression work, and HTML parsing that matches browsers so content cannot hide from the scan. Detection moves the same way, into what attachments and hidden text actually contain. Point releases keep carrying incompatible changes to digests and scoring, so operators need to read the notes on every update.
◆ Prediction
Expect more browser-parity fixes in HTML and URL handling, and attachment extraction beyond the SVG and OOXML set. The planned flip of allow_file_and_shm_inputs to false does not appear in the 4.2 notes, so it remains the breaking change to watch.
Alternatives to mailcow and Rspamd
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 Rspamd.
Netcore Cloud
Netcore's blog keeps pitching search-plus-email on one data core, with no product release.
Superhuman
Superhuman gives team admins a console and Enterprise a usage report that counts MCP.
Slack
Slack's CLI now points coding agents to its MCP server and Skills plugin
Synapse
Synapse opens the 1.165 cycle on schedule after two 1.164 patches
Whereby
Whereby folds three months into one digest and still lists nothing specific
See all mailcow alternatives → · See all Rspamd alternatives →
Recent activity from mailcow and Rspamd
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 14d agomailcow🎃🐮 Mooctober 2026 | Security Update: PHP 8.2.35, SOGo 5.12.12 & Nginx 1.30.6
- 15d agoRspamd4.2.3: ARC trust fix, merged RBL queries, browser-style HTML parsing
- 25d agoRspamd4.2.2: crypto wallet detection and changed MIME digests
- 1mo agomailcow2026-09a: Rspamd 4.2.1 and postfix-tlspol bumps
- 1mo agoRspamd4.2.1: critical HTTP and memory-safety fixes
- 1mo agomailcow🍂🐮 Mootember 2026 | Unbound 1.26.1, SOGo 5.12.11 & Redis 7.4.11
- 1mo agoRspamd4.2.0: public suffix lookup and attachment content extraction
- 2mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision B
- 2mo agoRspamdCloses an arbitrary file read reachable by any TCP client
- 3mo agomailcow🏖️🐮 Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3 - Revision A
- 3mo agoRspamdController accepted any password on a malformed hash
- 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 Rspamd?
They serve adjacent needs but don't currently overlap on shipped themes. mailcow and Rspamd 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 Rspamd?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. mailcow and Rspamd 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 Rspamd?
Top Rspamd alternatives in Comms are ranked by recent ship velocity. Browse the "Rspamd alternatives" section above for the current picks, or visit /alternatives/rspamd for the full list with editorial commentary on each.