Header Analyzer
Paste the raw headers of an email to see its delivery path and authentication results (SPF/DKIM/DMARC). This runs entirely in your browser — nothing is sent to our server.
Frequently asked questions
What can the Header Analyzer tell me?
Paste in the full raw headers of an email (not just what your inbox shows) and it reconstructs the delivery path hop by hop, plus whether the message passed SPF, DKIM, and DMARC — useful for tracking down why a message was delayed, misrouted, or flagged as spam.
Is my pasted header data sent to your server?
No. This tool runs entirely in your browser using JavaScript — pasted headers are never transmitted anywhere.
Is this free to use?
Yes, completely free, with no signup or account required.