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Dovecot vs Stalwart

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

Shared themes:imap

Dovecot vs Stalwart: at a glance

FeatureDovecotStalwart
SectorCommsComms
Velocity score0.05.0
Sparks · 30d00
Top themesmail server, imap, cve cadence, config rewritemail-server, jmap, imap, rfc-compliance
Last editorial update12d ago23h ago
WebsiteVisit →Visit →

What is Dovecot?

Dovecot's 2.4 rewrite is still being paid for — twelve CVEs across two releases, two of them 2.4 regressions.

Dovecot 2.4 broke configuration compatibility outright in January 2025 and the line has been stabilizing ever since. The last two releases are dominated by security work: 2.4.3 shipped eight CVEs including SQL and LDAP injection when auth_username_chars is empty — both labelled v2.4 regressions — and 2.4.4 added four more, among them a fakeable CRAM channel binding and an incomplete earlier fix. Alongside that, 2.4.4 permanently drops root privileges in indexer-worker, quota-status and script-login before they serve requests.

Read the full Dovecot trajectory →

What is Stalwart?

Stalwart is chasing mail RFCs and its own storage layer at the same time

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

Read the full Stalwart trajectory →

Dovecot vs Stalwart: editorial side-by-side

D
Dovecot
COMMS
0.0

Dovecot's 2.4 rewrite is still being paid for — twelve CVEs across two releases, two of them 2.4 regressions.

◆ Current state

Dovecot 2.4 broke configuration compatibility outright in January 2025 and the line has been stabilizing ever since. The last two releases are dominated by security work: 2.4.3 shipped eight CVEs including SQL and LDAP injection when auth_username_chars is empty — both labelled v2.4 regressions — and 2.4.4 added four more, among them a fakeable CRAM channel binding and an incomplete earlier fix. Alongside that, 2.4.4 permanently drops root privileges in indexer-worker, quota-status and script-login before they serve requests.

◆ Where it's heading

The 2.4 line is a rewrite absorbing its own cost. Dependencies are being replaced rather than pinned — libicu swapped for an in-house unicode library, libpcre2 brought in for regular expressions — and the process model is being tightened, with permanent privilege drops and a reworked service_reuse_port that pre-creates one socket per process. IMAP4rev2 and UTF-8 mail remain behind build flags and config toggles, so the modern-protocol work is real but deliberately unshipped.

◆ Prediction

Expect the CVE cadence to keep tracking the areas the rewrite touched — auth escaping, IMAP parsing limits and the variable expansion introduced in 2.4 — rather than long-settled code. The experimental IMAP4rev2 and mail_utf8 flags are the obvious candidates to graduate once the security churn slows, though nothing in these entries sets a date.

S5.0

Stalwart is chasing mail RFCs and its own storage layer at the same time

◆ Current state

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

◆ Where it's heading

Two threads run through every release. One is RFC coverage across IMAP, JMAP, CalDAV and WebDAV, implemented close to the specification including drafts. The other is a long tail of protocol-conformance fixes, many of them cases where JMAP and IMAP disagreed about the same state. The newest release adds a third: memory and scheduling limits, which is what a server codebase starts doing when deployments get large enough for defaults to hurt.

◆ Prediction

Expect continued RFC additions across the JMAP and IMAP surfaces, with more of the storage-tuning work that v0.16.18 started as RocksDB deployments scale.

Alternatives to Dovecot 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 Dovecot or Stalwart.

See all Dovecot alternatives → · See all Stalwart alternatives →

Recent activity from Dovecot and Stalwart

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

  1. 1d agoStalwartResource limits arrive for inbound reports and RocksDB caches
  2. 8d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
  3. 16d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
  4. 23d agoStalwartFix-only release: JMAP semantics and a credential escalation
  5. 29d agoStalwartVAPID lands for JMAP Web Push
  6. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  7. 3mo agoDovecotFour more CVEs, and root is dropped permanently
  8. 4mo agoDovecotEight CVEs, two of them 2.4 regressions
  9. 9mo agoDovecotlibicu replaced in-house; IMAP4rev2 lands experimental
  10. 1y agoDovecotFirst 2.4 patch, carrying the new signing key
  11. 1y agoDovecotDovecot v2.4.0
  12. 2y agoDovecotHeader limits imposed after CPU exhaustion CVEs

Frequently asked questions

What is the difference between Dovecot and Stalwart?

Both compete on the same themes — imap — within Comms. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), 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 Dovecot better than Stalwart?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), 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 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 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.