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Stalwart vs Superhuman

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

Stalwart vs Superhuman: at a glance

FeatureStalwartSuperhuman
SectorCommsComms
Velocity score5.07.5
Sparks · 30d02
Top themesemail-standards, jmap, imap, dmarcmcp, auto-drafts, agent-native, multi-account
Last editorial update23h ago13d ago
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What is Stalwart?

Stalwart is shipping email's next-generation auth stack while the specs are still in draft.

Stalwart is an all-in-one mail and collaboration server — SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV in one binary — releasing every one to two weeks on the 0.16.x line. The last two months read as a standards campaign: DKIM2 and the full DMARCbis set in 0.16.12, VAPID push in 0.16.14, FreeBSD support in 0.16.13, and a run of IMAP extensions (UIDONLY, UIDBATCHES, MESSAGELIMIT/SAVELIMIT) in 0.16.17. Between the additions, most of each release is JMAP conformance repair driven by the jmap-test-suite.

Read the full Stalwart trajectory →

What is Superhuman?

Superhuman is rebuilding around the assistant: pre-drafted replies and multi-account MCP.

Superhuman ships small and often, and its releases now split cleanly in two. One half is conventional client work — calendar on Android, multi-day views on iPhone and iPad, personalized availability sharing. The other is an aggressive agent surface: Auto Drafts 2.0 pre-drafts a reply to every message that needs one, and the Mail MCP now drives multiple Gmail and Outlook accounts from Claude, ChatGPT and Codex.

Read the full Superhuman trajectory →

Stalwart vs Superhuman: editorial side-by-side

S5.0

Stalwart is shipping email's next-generation auth stack while the specs are still in draft.

◆ Current state

Stalwart is an all-in-one mail and collaboration server — SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV in one binary — releasing every one to two weeks on the 0.16.x line. The last two months read as a standards campaign: DKIM2 and the full DMARCbis set in 0.16.12, VAPID push in 0.16.14, FreeBSD support in 0.16.13, and a run of IMAP extensions (UIDONLY, UIDBATCHES, MESSAGELIMIT/SAVELIMIT) in 0.16.17. Between the additions, most of each release is JMAP conformance repair driven by the jmap-test-suite.

◆ Where it's heading

The project is building toward being the reference implementation of the modern mail stack — JMAP first, with the classic protocols held at parity rather than left behind. The fix lists have shifted in character over these eight releases: less "feature does not work", more "spec detail is wrong", which is what a codebase looks like as it converges on conformance. Security and multi-tenancy fixes keep appearing alongside the protocol work, indicating real deployments are exercising the newer subsystems.

◆ Prediction

The next releases most likely track revisions to the drafts already implemented — DKIM2, JMAP push and the calendar drafts are all still moving — rather than adding another protocol surface. Expect continued JMAP conformance fixes until the test suite stops producing them.

S7.5

Superhuman is rebuilding around the assistant: pre-drafted replies and multi-account MCP.

◆ Current state

Superhuman ships small and often, and its releases now split cleanly in two. One half is conventional client work — calendar on Android, multi-day views on iPhone and iPad, personalized availability sharing. The other is an aggressive agent surface: Auto Drafts 2.0 pre-drafts a reply to every message that needs one, and the Mail MCP now drives multiple Gmail and Outlook accounts from Claude, ChatGPT and Codex.

◆ Where it's heading

The centre of gravity is moving off Superhuman's own client. Each recent release makes the mailbox more usable from somewhere else — first a Codex plugin with prebuilt workflows, then parallel search across every connected account — while in-app work is mostly mobile parity. Superhuman is positioning as the mail layer assistants call, and it names the single-account limit of the first-party Gmail and Outlook connectors as the reason to switch.

◆ Prediction

Expect the MCP surface to keep absorbing the features that only the client could do — Split Inbox triage, Read Statuses, Smart Send are already listed — with the native apps continuing to trail on platform parity.

Alternatives to Stalwart and Superhuman

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 Superhuman.

See all Stalwart alternatives → · See all Superhuman alternatives →

Recent activity from Stalwart and Superhuman

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

  1. 1d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
  2. 9d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
  3. 13d agoSuperhumanMultiple email accounts in Claude, ChatGPT, and MCP 🤖
  4. 15d agoStalwartFix-only release: JMAP semantics and a credential escalation
  5. 22d agoStalwartVAPID lands for JMAP Web Push
  6. 29d agoSuperhumanAuto Drafts 2.0 ✨
  7. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  8. 1mo agoStalwartDKIM2 and the full DMARCbis suite ship in one release
  9. 1mo agoSuperhumanMulti-day views on iPhone & iPad 📆
  10. 1mo agoSuperhumanCalendar on Android 💚
  11. 1mo agoSuperhumanSuperhuman Mail Codex plugin 🤖
  12. 2mo agoSuperhumanPersonalize share availability ✨

Frequently asked questions

What is the difference between Stalwart and Superhuman?

They serve adjacent needs but don't currently overlap on shipped themes. Superhuman is currently shipping more aggressively (velocity 7.5 vs 5.0), with 2 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 Superhuman?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Superhuman is currently shipping more aggressively (velocity 7.5 vs 5.0), with 2 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 Superhuman?

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