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Stalwart vs Trengo

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

Stalwart vs Trengo: at a glance

FeatureStalwartTrengo
SectorCommsComms
Velocity score5.00.0
Sparks · 30d00
Top themesemail-standards, jmap, imap, dmarcwhatsapp, ai-agents, journeys, integrations
Last editorial update1d ago3mo ago
WebsiteVisit →

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 Trengo?

Trengo doubles down on WhatsApp depth and self-improving AI agents.

Trengo is layering richer WhatsApp capabilities — typing indicators, template headers, dynamic URL buttons — on top of an AI Agent 2.0 push that now ingests Notion and Shopify data and identifies its own knowledge gaps from escalations. The product is splitting effort between making WhatsApp feel like a first-class messaging channel and turning the AI agent into a continuously self-improving system.

Read the full Trengo trajectory →

Stalwart vs Trengo: 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.

T
Trengo
COMMS
0.0

Trengo doubles down on WhatsApp depth and self-improving AI agents.

◆ Current state

Trengo is layering richer WhatsApp capabilities — typing indicators, template headers, dynamic URL buttons — on top of an AI Agent 2.0 push that now ingests Notion and Shopify data and identifies its own knowledge gaps from escalations. The product is splitting effort between making WhatsApp feel like a first-class messaging channel and turning the AI agent into a continuously self-improving system.

◆ Where it's heading

The company is moving from messaging inbox toward an automation runtime where WhatsApp is the primary surface and an AI agent handles the long tail. Recent work consistently extends Journey workflows — first dynamic URL buttons, then template headers — suggesting Journeys is becoming the central canvas where merchants compose conversational commerce flows.

◆ Prediction

Expect typing indicators to extend to AI Agents and Flowbots, as already pre-announced, and expect more commerce-system integrations beyond Shopify — Magento or BigCommerce would close obvious gaps for the same buyer.

Alternatives to Stalwart and Trengo

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 Trengo.

See all Stalwart alternatives → · See all Trengo alternatives →

Recent activity from Stalwart and Trengo

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. 16d 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. 5mo agoTrengoTyping Indicators in WhatsApp
  8. 5mo agoTrengoWhatsApp Template Dynamic URL Buttons via API
  9. 5mo agoTrengoWhatsApp Templates with Headers in Journeys
  10. 6mo agoTrengoAI Agent 2.0: Notion and Shopify Integrations
  11. 6mo agoTrengoDynamic URL Buttons in Journeys (WhatsApp)
  12. 6mo agoTrengoAI Agent 2.0: Knowledge Gap Detection

Frequently asked questions

What is the difference between Stalwart and Trengo?

They serve adjacent needs but don't currently overlap on shipped themes. 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 Trengo?

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 Trengo?

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