Labs/Demos/Email Header Analyzer
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Email Header Analyzer

Local analysisHeader parsingNothing saved

This checks the authentication fields in the headers you provide. It does not contact mail servers or verify the actual sender.

Raw Email Headers

Paste the full header block below. Everything runs in your browser.

Runs locally in your browser. Maximum input size: 25,000 characters.
Analysis is based solely on the header text provided. No external verification or DNS lookups are performed.
Authentication can show whether a message lines up with the sending domain's rules. It cannot prove the sender's intent or guarantee the email is safe.
What this demo shows
  • Authentication Summary for SPF, DKIM, and DMARC
  • Sender Identity comparison across From, Return-Path, and Reply-To
  • Received Path mail routing chain
  • Potential indicators that may deserve closer review
Ready to analyze

Paste a header block and click Analyze Headers to view authentication results, sender identity analysis, received path details, and potential indicators.

Input hardening: This demo strips unsafe control characters, blocks oversized input, and warns when pasted content looks unlike normal email headers. No data is stored or transmitted.