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Apache RocketMQ vs Stalwart

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

Apache RocketMQ vs Stalwart: at a glance

FeatureApache RocketMQStalwart
SectorCommsComms
Velocity score2.55.0
Sparks · 30d00
Top themesmessage-broker, rocksdb, lite-mode, dledgeremail-server, jmap, interoperability, self-hosted
Last editorial update2mo ago13h ago
WebsiteVisit →Visit →

What is Apache RocketMQ?

The RocksDB migration reaches native code as the legacy DLedger broker mode is marked for removal

The 5.x line continues to replace storage internals with RocksDB and to retire the mechanisms it supersedes. 5.5.1, the first release since April, swaps the pure-Java ConsumeQueue compaction filter for a native RocksDB CqCompactionFilter behind a cross-platform JNI shim, drops the shaded rocketmq-rocksdb dependency, and deprecates the legacy Broker DLedger mode. Lite Mode, introduced in 5.5.0, received stability work rather than the client-side adoption path it still needs. Alongside this sit fastjson 1.x removal and a long list of Proxy, Pop and Remoting fixes.

Read the full Apache RocketMQ trajectory →

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.

Read the full Stalwart trajectory →

Apache RocketMQ vs Stalwart: editorial side-by-side

A2.5

The RocksDB migration reaches native code as the legacy DLedger broker mode is marked for removal

◆ Current state

The 5.x line continues to replace storage internals with RocksDB and to retire the mechanisms it supersedes. 5.5.1, the first release since April, swaps the pure-Java ConsumeQueue compaction filter for a native RocksDB CqCompactionFilter behind a cross-platform JNI shim, drops the shaded rocketmq-rocksdb dependency, and deprecates the legacy Broker DLedger mode. Lite Mode, introduced in 5.5.0, received stability work rather than the client-side adoption path it still needs. Alongside this sit fastjson 1.x removal and a long list of Proxy, Pop and Remoting fixes.

◆ Where it's heading

The storage convergence is now deep enough to cross the JNI boundary — RocksDB is no longer an alternate index but the substrate, and the project is willing to take on native build complexity across platforms to get its performance. In parallel, deprecating legacy Broker DLedger narrows the replication story toward the jRaft controller, cutting a maintenance branch rather than carrying both. Lite Mode remains the open bet: it is being maintained but not yet extended outward to clients.

◆ Prediction

With legacy DLedger deprecated rather than removed, a following release that deletes it outright is the natural next step. Whether Lite Mode gains the client and proxy support it needs is still unresolved — 5.5.1 fixed it without broadening it.

S5.0

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.

Alternatives to Apache RocketMQ 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 Apache RocketMQ or Stalwart.

See all Apache RocketMQ alternatives → · See all Stalwart alternatives →

Recent activity from Apache RocketMQ and Stalwart

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

  1. 15d agoStalwartv0.16.27: IMAP SEARCH RETURN and iTIP time zone fixes
  2. 22d agoStalwartv0.16.26 fixes RocksDB rewriting every blob on compaction
  3. 28d agoStalwartv0.16.25: JMAP MaskedEmail and Autodiscover fixes
  4. 1mo agoStalwartv0.16.24: PowerDNS provider and phishing list matching fix
  5. 1mo agoStalwartv0.16.23: nested list delivery and lost DSN fixes
  6. 1mo agoStalwartv0.16.22: STARTTLS session reset and DMARC result fixes
  7. 2mo agoApache RocketMQ5.5.1: native RocksDB compaction filter, legacy DLedger mode deprecated
  8. 6mo agoApache RocketMQ5.5.0 adds Lite Mode, a lightweight subscription path for AI workloads ⚡
  9. 10mo agoApache RocketMQ5.4.0: priority messages and RocksDB-backed timer, transaction and index
  10. 10mo agoApache RocketMQ5.3.4: TimerWheel snapshots and Netty, OpenTelemetry upgrades
  11. 1y agoApache RocketMQ5.3.3 drops ACL 1.0 in favour of ACL 2.0
  12. 1y agoApache RocketMQ5.3.2: RocksDB-based Pop consumption enters alpha

Frequently asked questions

What is the difference between Apache RocketMQ and Stalwart?

They serve adjacent needs but don't currently overlap on shipped themes. Stalwart 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 Apache RocketMQ 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 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 Apache RocketMQ?

Top Apache RocketMQ alternatives in Comms are ranked by recent ship velocity. Browse the "Apache RocketMQ alternatives" section above for the current picks, or visit /alternatives/rocketmq 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.