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Session vs Stalwart

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

Session vs Stalwart: at a glance

FeatureSessionStalwart
SectorCommsComms
Velocity score3.85.0
Sparks · 30d00
Top themesprivate-messaging, encryption, post-quantum, funding-crisisemail-standards, jmap, imap, dmarc
Last editorial update1mo ago21h ago
WebsiteVisit →Visit →

What is Session?

Session pulls back from a funding crisis as community support revives development

Session's recent feed is dominated by survival, not shipping: a cofounder's personal appeal warning the project might not continue, followed by news that community donations, node operation, and awareness restored its runway and development will resume. Underneath sits real roadmap work — Session Protocol V2 (forward secrecy, post-quantum crypto) and the long-running Session Pro Beta.

Read the full Session trajectory →

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 →

Session vs Stalwart: editorial side-by-side

S
Session
COMMS
3.8

Session pulls back from a funding crisis as community support revives development

◆ Current state

Session's recent feed is dominated by survival, not shipping: a cofounder's personal appeal warning the project might not continue, followed by news that community donations, node operation, and awareness restored its runway and development will resume. Underneath sits real roadmap work — Session Protocol V2 (forward secrecy, post-quantum crypto) and the long-running Session Pro Beta.

◆ Where it's heading

The product spent recent months in existential mode and has now stabilized enough to resume development and keep critical infrastructure running. The technical direction — post-quantum cryptography and forward secrecy in Protocol V2, plus Pro Beta features — remains the substance, but momentum hinges on the donation-funded model that just rescued it.

◆ Prediction

Expect development to resume around Protocol V2 and the Session Pro Beta, with continued reliance on community funding; pace depends on whether the donation rebound holds.

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.

Alternatives to Session 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 Session or Stalwart.

See all Session alternatives → · See all Stalwart alternatives →

Recent activity from Session and Stalwart

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. 15d agoStalwartFix-only release: JMAP semantics and a credential escalation
  4. 22d agoStalwartVAPID lands for JMAP Web Push
  5. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  6. 1mo agoStalwartDKIM2 and the full DMARCbis suite ship in one release
  7. 2mo agoSessionThe Future of Session
  8. 4mo agoSessionA Personal Appeal From Cofounder of Session - Chris McCabe
  9. 6mo agoSessionRotating keys for Session repos
  10. 8mo agoSessionSession Pro Beta update: December 2025
  11. 8mo agoSessionSession Protocol V2: PFS, Post-Quantum and the Future of Private Messaging
  12. 9mo agoSessionRemoving screenshot alerts from Session

Frequently asked questions

What is the difference between Session and Stalwart?

They serve adjacent needs but don't currently overlap on shipped themes. Stalwart is currently shipping more aggressively (velocity 5.0 vs 3.8), 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 Session 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 3.8), 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 Session?

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