Product history

Changelog

Compatibility guidance changes as email clients change. SigLint publishes material rule and methodology updates so findings remain auditable instead of silently changing behind a score.

15 August 2026 · Visual clarity update

Client-aware iconography

  • Added restrained Outlook, Gmail and general-email client markers to the homepage compatibility scope.
  • Added client icons and counts to checker filter chips.
  • Added client badges and subtle client-specific borders to findings for faster scanning.
  • Added a clearer illustrated empty state for the findings panel.
  • Added lightweight client/category markers to the Rules Library without turning the interface into a logo wall.
15 August 2026 · Fix and verify update

Occurrence-aware diagnostics and portable reports

  • Added multiple-occurrence detection for regex-backed rules instead of stopping at the first match.
  • Added an occurrence count and individual line/column jumps for repeated problems.
  • Made the re-check delta occurrence-aware, so partially fixing repeated problems is visible even when the rule type remains.
  • Added character count and Ctrl/Cmd + Enter checking.
  • Added copy-as-Markdown and print-ready reports; original signature HTML is intentionally excluded.
  • Added a testable report-state module and expanded regression tests.
  • Corrected the image-dimensions detector to flag a missing width or a missing height.
15 August 2026 · Diagnostic evidence update

Source-aware findings

  • Added line and column locations for regex-backed findings.
  • Added “View in HTML” source jumps and offending code snippets.
  • Added first-party evidence metadata and verification dates for selected Microsoft and Google backed rules.
  • Added two Microsoft-backed Classic Outlook line-height checks.
  • Expanded current rule count from 20 to 22.
  • Added a public Rules Library, expanded methodology, About page and transparent product changelog.
15 August 2026 · Checker UX update

Professional report controls

  • Added sticky HTML editor on desktop.
  • Added severity and client filters.
  • High-severity findings open by default; medium and low findings are collapsible.
  • Replaced the native file picker presentation with a custom Upload HTML control.
  • Connected supported findings to detailed troubleshooting guides.
  • Added clear/start-over and report completion actions.
15 August 2026 · Release 0.1

Initial public checker

  • Launched browser-local HTML signature analysis.
  • Added Outlook Classic, Gmail, image, layout and accessibility checks.
  • Published initial troubleshooting guides, methodology, privacy, sitemap, robots.txt and llms.txt.
  • No accounts, payments, backend storage, AI rewriting or render farm.

How rule changes are handled

Material changes to a rule’s detector, client scope, severity or evidence should be recorded here. High-impact rules should also carry regression fixtures in the repository.

Browse the current Rules Library →