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Email Header Analyzer

Paste, drag in, or upload full email headers (a .txt export, or just the raw header block copied from your mail client's "show original"/"view source"). Extracts the common fields, walks every Received hop in true chronological order (the raw file lists them newest-first — a classic thing to get backwards) with the delay between each, flags private/RFC1918 IPs and sending-hostname mismatches, summarizes SPF/DKIM/DMARC from Authentication-Results, and extracts every IP, domain, URL, and email address found. Runs entirely in your browser: nothing is looked up (no DNS, no reputation checks) and nothing is ever transmitted anywhere.

Notes

Hostname-mismatch detection compares the claimed sending host (after from) against the parenthetical name the receiving server observed, and only flags a genuine mismatch when both are present and share no common domain suffix — it will never flag a hop where only one name is available, since there's nothing to compare. This is a heuristic, not proof of forgery: legitimate infrastructure occasionally has mismatched naming too, especially behind load balancers or third-party mail relays.