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Dovecot vs Synapse

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

Dovecot vs Synapse: at a glance

FeatureDovecotSynapse
SectorCommsComms
Velocity score2.55.0
Sparks · 30d00
Top themesemail-infrastructure, imap, security-hardening, cve-responsematrix-protocol, homeserver, security-patches, spec-compliance
Last editorial update2mo ago1d ago
WebsiteVisit →Visit →

What is Dovecot?

Dovecot's 2.4 branch is being hardened release by release after a breaking rewrite.

Dovecot is the IMAP and POP3 server behind a large share of the world's mailboxes. The 2.4 branch opened in January 2025 with a deliberately incompatible release — configuration files must be rewritten, the plugin section is gone, and several long-standing features were removed outright — and every release since has been consolidation on top of it. The pattern is consistent: each point release leads with critical CVE fixes, then lists incremental changes. The latest, 2.4.5, carries twelve CVEs alongside post-quantum ML-KEM support, full-text phrase searching and a throttling response code.

Read the full Dovecot trajectory →

What is Synapse?

Synapse 1.164 advertises Matrix v1.16 and v1.17 amid a run of dependency security patches

Synapse keeps its two-to-three-week cycle of candidates and stables. 1.164.0 went stable on 27 October with support for Matrix v1.16 and v1.17 and a dedicated endpoint for scheduling delayed events (MSC4140). The surrounding releases are security dependency bumps: certifi, a rustls-webpki update that distrusts the compromised eMudhra intermediate CAs, Pillow 13.0.0 for critical image-handling flaws, and msgpack against memory exhaustion on the public room list.

Read the full Synapse trajectory →

Dovecot vs Synapse: editorial side-by-side

D
Dovecot
COMMS
2.5

Dovecot's 2.4 branch is being hardened release by release after a breaking rewrite.

◆ Current state

Dovecot is the IMAP and POP3 server behind a large share of the world's mailboxes. The 2.4 branch opened in January 2025 with a deliberately incompatible release — configuration files must be rewritten, the plugin section is gone, and several long-standing features were removed outright — and every release since has been consolidation on top of it. The pattern is consistent: each point release leads with critical CVE fixes, then lists incremental changes. The latest, 2.4.5, carries twelve CVEs alongside post-quantum ML-KEM support, full-text phrase searching and a throttling response code.

◆ Where it's heading

Two things are being worked at once. Security is the visible half, and the volume is striking — resource-exhaustion and parser issues in IMAP THREAD, LIST and ID, a CRIME-style compression side channel, an authentication bypass through XCLIENT forwarding. The quieter half is that fixes are increasingly gated behind version declarations: the THREAD fix needs a new index format enabled only by raising dovecot_storage_version. That mechanism, introduced with 2.4.0, is now doing real work, letting operators take format changes on their own schedule.

◆ Prediction

Experimental flags for mail UTF-8 and IMAP4rev2 have carried unchanged through every 2.4 release so far; the next branch-defining move is one of those graduating to default rather than another security round.

S
Synapse
COMMS
5.0

Synapse 1.164 advertises Matrix v1.16 and v1.17 amid a run of dependency security patches

◆ Current state

Synapse keeps its two-to-three-week cycle of candidates and stables. 1.164.0 went stable on 27 October with support for Matrix v1.16 and v1.17 and a dedicated endpoint for scheduling delayed events (MSC4140). The surrounding releases are security dependency bumps: certifi, a rustls-webpki update that distrusts the compromised eMudhra intermediate CAs, Pillow 13.0.0 for critical image-handling flaws, and msgpack against memory exhaustion on the public room list.

◆ Where it's heading

The homeserver tracks the spec closely, stabilising MSCs as they land in Matrix releases, while backporting each security bump to the previous stable line. Sticky Events and User Status work suggest continued alignment with newer client features.

◆ Prediction

1.165 release candidates should follow within about two weeks, likely with further MSC stabilisations.

Alternatives to Dovecot and Synapse

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 Dovecot or Synapse.

See all Dovecot alternatives → · See all Synapse alternatives →

Recent activity from Dovecot and Synapse

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

  1. 2d agoSynapseSynapse 1.164.2 patch release
  2. 7d agoSynapseSynapse 1.164.1: msgpack memory-exhaustion fix, status clearing
  3. 8d agoSynapseSynapse 1.164.0: Matrix v1.16/v1.17 support goes stable
  4. 12d agoSynapseSynapse 1.164.0rc3: Pillow 13 security bump
  5. 12d agoSynapseSynapse 1.163.2: Pillow critical security backport
  6. 13d agoSynapseSynapse 1.164.0rc2: certificate trust updates
  7. 2mo agoDovecotTwelve CVEs fixed; ML-KEM and full-text phrase search arrive
  8. 5mo agoDovecotCVE fixes in variable expansion and CRAM-SHA authentication
  9. 6mo agoDovecotCVE fixes for base64 auth DoS and decode2text
  10. 1y agoDovecotAuth cache key collision fixed; libpcre2 becomes a dependency
  11. 1y agoDovecot2.4 branch signing key rotates; packages break 2.3 configs
  12. 1y agoDovecotDovecot 2.4 lands: configs must be rewritten, director removed ⚡

Frequently asked questions

What is the difference between Dovecot and Synapse?

They serve adjacent needs but don't currently overlap on shipped themes. Synapse is currently shipping more aggressively (velocity 5.0 vs 2.5), 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 Dovecot better than Synapse?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Synapse is currently shipping more aggressively (velocity 5.0 vs 2.5), 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 Dovecot?

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

What are the best alternatives to Synapse?

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