InboxProof

InboxProof is a web app that renders your newsletter exactly as it will appear across major email clients and dark/light modes, then flags the real-world issues that hurt clicks and trust: broken tracking parameters, clipped emails, image blocking, spammy phrasing, missing alt text, and layout shifts on mobile. Instead of generic “spam score” fluff, it focuses on practical, fixable problems with clear before/after previews and a short checklist you can hand to a writer or marketer. You paste HTML, connect your ESP, or upload a draft, then run a preflight that produces a shareable QA report. It’s built for small teams who can’t justify enterprise email testing suites but still get burned by rendering bugs and deliverability surprises. Optional AI assists by rewriting risky subject lines and suggesting simpler layouts, but the core value is deterministic testing and reproducible checks.