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Comparison · Comms
Stalwart vs VerneMQ
A side-by-side editorial comparison of Stalwart and VerneMQ — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:self-hosted
Stalwart vs VerneMQ: at a glance
What is Stalwart?
Stalwart keeps chasing standards nobody has implemented yet — DKIM2, DMARCbis, now JMAP email push.
Stalwart is a single-binary mail and collaboration server covering JMAP, IMAP, SMTP, CalDAV and CardDAV. The 0.16.x line ships roughly weekly and its additions cluster in one place: implementing IETF drafts and fresh RFCs ahead of the field, while a long tail of JMAP conformance and MTA edge-case fixes runs underneath. The latest release adds JMAP email delivery push notifications, completing a push stack built across the last three releases.
What is VerneMQ?
A slow, careful MQTT broker that spent two years landing one breaking storage change.
VerneMQ is in low-cadence maintenance on the 2.1.x line, with releases spaced months apart and a 2.1.3 release candidate open since April. The work is concentrated in the clustering metadata store (vmq_swc), the MQTT session state machine, and WebSocket listener behaviour — the parts operators actually file bugs against. Commercial binaries remain EULA-gated, so the open-source repo is the product surface and the packages are the business.
Stalwart vs VerneMQ: editorial side-by-side
Stalwart
5.0COMMS
Stalwart keeps chasing standards nobody has implemented yet — DKIM2, DMARCbis, now JMAP email push.
◆ Current state
Stalwart is a single-binary mail and collaboration server covering JMAP, IMAP, SMTP, CalDAV and CardDAV. The 0.16.x line ships roughly weekly and its additions cluster in one place: implementing IETF drafts and fresh RFCs ahead of the field, while a long tail of JMAP conformance and MTA edge-case fixes runs underneath. The latest release adds JMAP email delivery push notifications, completing a push stack built across the last three releases.
◆ Where it's heading
The push story is the clearest arc: Web Push payload and subscription fixes in 0.16.10, VAPID per RFC 9749 in 0.16.14, and the emailpush draft in 0.16.16. Parallel to it, 0.16.12 landed DKIM2 and the DMARCbis trio, and the fix lists keep narrowing toward strict-spec behaviour — DMARC alignment reporting, SMTP line-length limits, BDAT error codes. Stalwart is positioning as the reference implementation of modern mail standards rather than competing on features.
◆ Prediction
Expect the JMAP push work to keep filling in — subscription lifecycle, delivery semantics — alongside continued DKIM2 and DMARCbis refinement as those drafts move. The fix cadence suggests operational hardening around clustering and Redis locking is the other near-term thread.
VerneMQ
0.0COMMS
A slow, careful MQTT broker that spent two years landing one breaking storage change.
◆ Current state
VerneMQ is in low-cadence maintenance on the 2.1.x line, with releases spaced months apart and a 2.1.3 release candidate open since April. The work is concentrated in the clustering metadata store (vmq_swc), the MQTT session state machine, and WebSocket listener behaviour — the parts operators actually file bugs against. Commercial binaries remain EULA-gated, so the open-source repo is the product surface and the packages are the business.
◆ Where it's heading
The centre of gravity is correctness in clustered deployments, not new protocol capability. Recent releases keep tightening the same three areas — connection accounting under churn, proxy-header handling behind load balancers, and metadata sync for joining nodes — which reads as a broker being hardened for larger clusters rather than broadened. The RC-heavy release pattern (three RCs before 2.1.0, one open for 2.1.3) suggests a small team leaning on community testing before committing.
◆ Prediction
2.1.3 ships as a fix-consolidation release absorbing the remaining open PRs, with the retain-expiry default change carried through. Nothing in these entries points to a new protocol or storage direction after that.
Alternatives to Stalwart and VerneMQ
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 VerneMQ.
Elastic Email
A deliverability vendor ships DMARCRadar and lets case studies do the rest of the talking.
Twilio
Branded calling goes GA while the API surface gets quietly tightened and corrected.
Wire
Wire keeps a fortnightly production train, but most tags ship without published notes.
Telnyx
Telnyx is unbundling itself from the phone network and rebuilding as an agent platform.
Netcore Cloud
Netcore's blog is selling six production AI agents; the feed never shows them shipping.
See all Stalwart alternatives → · See all VerneMQ alternatives →
Recent activity from Stalwart and VerneMQ
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoStalwartv0.16.16 — JMAP email push, plus Redis lock and SMTP relay fixes
- 8d agoStalwartv0.16.15 — JMAP, MTA, and auth privilege fixes
- 15d agoStalwartv0.16.14 — VAPID Web Push plus push and calendar fixes
- 22d agoStalwartv0.16.13 — FreeBSD support and OAuth/JMAP fixes
- 29d agoStalwartv0.16.12 — DKIM2 and DMARCbis email-authentication support
- 1mo agoStalwartv0.16.11 — S/MIME encryption-at-rest and Redis Sentinel backend
- 3mo agoVerneMQ2.1.3 RC1: socket-close accounting fix, retain-expiry check off by default
- 4mo agoVerneMQ2.1.2 fixes WebSocket connection counts and X-Forwarded-For handling
- 10mo agoVerneMQ2.1.1 fixes syslog boot, drops default local listeners
- 1y agoVerneMQ2.1.0 lands a breaking on-disk metadata format ⚡
- 1y agoVerneMQ2.1.0-rc3 makes inter-node connect options configurable
- 1y agoVerneMQ2.1.0-rc2: single init_sync flag fix
Frequently asked questions
What is the difference between Stalwart and VerneMQ?
Both compete on the same themes — self-hosted — 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 Stalwart better than VerneMQ?
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 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 VerneMQ?
Top VerneMQ alternatives in Comms are ranked by recent ship velocity. Browse the "VerneMQ alternatives" section above for the current picks, or visit /alternatives/vernemq for the full list with editorial commentary on each.