1. Header triage
Paste full headers to see SPF, DKIM, DMARC, From, Return-Path and signing-domain alignment.
Analyse headers →Email delivery triage without exposing private headers
Paste the fault. Get the reason. Fix the sender.
Email Fault Finder turns bounces, headers and DNS records into a practical diagnosis: what failed, why it failed, and what to change next. Pasted email data stays in your browser.
Three ways to find the fault
2. Bounce decoder
Paste the rejection or non-delivery report and get a plain-English explanation of the likely cause.
Decode bounce →3. DNS checker
Check SPF, DMARC, MX and a known DKIM selector, with colour-coded findings.
Check DNS →The standout feature to build towards
The product should become an email fault triage assistant: paste a bounce or headers, then receive a concise verdict such as “SendGrid is sending as your domain, but DKIM is only aligned to SendGrid, so DMARC fails”. That is the real gap, not another generic SPF checker.
Email headers can contain addresses, IPs, tenant IDs, message IDs and routing data. Email Fault Finder is designed so pasted diagnostic content can be parsed in the browser. DNS lookups only need domain names, not the full header or bounce text.