Email header analyzer
🔒 Runs locally in your browser. Nothing you enter is uploaded.
How to use it
- Copy the full headers (Outlook: File → Properties; Gmail: Show original).
- Paste them into the box.
- Review the authentication results and red flags.
Frequently asked questions
What does DMARC fail mean?
The visible From domain wasn't authenticated by SPF or DKIM in alignment, a strong sign of spoofing.
Why check Reply-To?
BEC attackers often send from a look-alike address and route replies to a different domain.
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