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Comparison · Comms
Stalwart vs Rspamd
A side-by-side editorial comparison of Stalwart and Rspamd — release velocity, themes, recent moves, and the top alternatives to consider.
Stalwart vs Rspamd: at a glance
What is Stalwart?
Stalwart's weekly releases have turned from new standards to correctness fixes.
Stalwart's releases since v0.16.20 are dominated by long Fixed lists across IMAP, JMAP, MTA, DMARC and iTIP. Additions have been small: a PowerDNS provider in 0.16.24, sd_notify and JMAP mailbox behavior in 0.16.26. The most consequential repair is a RocksDB bug in 0.16.26 that rewrote every stored blob on each compaction of the blobs column family, about once per 128MB of new mail.
What is Rspamd?
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
Rspamd 4.3.0 on November 13 is a correctness release with a long incompatible-changes list. SPF records are now evaluated in term order, closing a case where an explicit -ip4 deny could be overridden by a broader allow. DKIM rejects RSA keys under 1024 bits and signatures with duplicate tags, DMARC no longer drops a policy over an unknown tag, URL mismatches are scored apart from phishing, and PDF text extraction and archive unpacking change their output. Critical fixes cover a header line that could abort a worker from one unauthenticated HTTP request.
Stalwart vs Rspamd: editorial side-by-side
Stalwart
5.0COMMS
Stalwart's weekly releases have turned from new standards to correctness fixes.
◆ Current state
Stalwart's releases since v0.16.20 are dominated by long Fixed lists across IMAP, JMAP, MTA, DMARC and iTIP. Additions have been small: a PowerDNS provider in 0.16.24, sd_notify and JMAP mailbox behavior in 0.16.26. The most consequential repair is a RocksDB bug in 0.16.26 that rewrote every stored blob on each compaction of the blobs column family, about once per 128MB of new mail.
◆ Where it's heading
After the SCIM v2 release in August, the project has shifted from extending coverage to making existing coverage hold up under real use. The bug reports now describe specific interoperability cases, such as Apple Calendar duplicates and DMARC report formatting, which suggests production traffic is driving the queue. The weekly cadence itself has not changed.
◆ Prediction
Expect more weekly fix releases on the same pattern. The entries show no sign of the next major capability, so its timing is unclear.
Rspamd
5.0COMMS
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
◆ Current state
Rspamd 4.3.0 on November 13 is a correctness release with a long incompatible-changes list. SPF records are now evaluated in term order, closing a case where an explicit -ip4 deny could be overridden by a broader allow. DKIM rejects RSA keys under 1024 bits and signatures with duplicate tags, DMARC no longer drops a policy over an unknown tag, URL mismatches are scored apart from phishing, and PDF text extraction and archive unpacking change their output. Critical fixes cover a header line that could abort a worker from one unauthenticated HTTP request.
◆ Where it's heading
Since 4.1, every release has hardened parsers and closed memory-safety and trust gaps; 4.3 applies the same pass to the authentication standards themselves (SPF, DKIM, DMARC, ARC) and to content extraction. Operators should expect scores and fuzzy hashes to shift after upgrading, because the project now favours spec-correct results over backward-compatible ones.
◆ Prediction
A 4.3.x point release fixing regressions from these behaviour changes is the likely next step, as 4.2.1 followed 4.2.0 within two weeks.
Alternatives to Stalwart 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 Stalwart or Rspamd.
Salesmsg
Salesmsg adds call-back requests and a one-click Emergency Stop for all outbound texts.
Element
Element 1.12.35 follows the call picture-in-picture release with one desktop storage fix.
Krisp
Krisp moves call transcripts and live captions to cloud transcription in KrispCX 2.84.4.
Misskey
Misskey 2026.11 ships: a leaner start script, and Node.js 22 no longer boots.
SlickText
SlickText's feed is all SMS buying guides; no product release has surfaced since RCS.
See all Stalwart alternatives → · See all Rspamd alternatives →
Recent activity from Stalwart and Rspamd
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 22h agoRspamd4.3.0: SPF order fix, stricter DKIM, new truncation symbols
- 24d agoRspamd4.2.3: ARC trust fix, merged RBL queries, browser-style HTML parsing
- 26d agoStalwartv0.16.27: IMAP SEARCH RETURN and iTIP time zone fixes
- 1mo agoStalwartv0.16.26 fixes RocksDB rewriting every blob on compaction
- 1mo agoRspamd4.2.2: crypto wallet detection and changed MIME digests
- 1mo agoStalwartv0.16.25: JMAP MaskedEmail and Autodiscover fixes
- 1mo agoRspamd4.2.1: critical HTTP and memory-safety fixes
- 1mo agoStalwartv0.16.24: PowerDNS provider and phishing list matching fix
- 1mo agoStalwartv0.16.23: nested list delivery and lost DSN fixes
- 1mo agoRspamd4.2.0: public suffix lookup and attachment content extraction
- 2mo agoStalwartv0.16.22: STARTTLS session reset and DMARC result fixes
- 3mo agoRspamdCloses an arbitrary file read reachable by any TCP client
Frequently asked questions
What is the difference between Stalwart and Rspamd?
They serve adjacent needs but don't currently overlap on shipped themes. Stalwart 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 Stalwart better than Rspamd?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart 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 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.
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.