Free browser-local comparison
Email Authentication Comparison
Compare two received message headers side by side. See what was reported, which server reported it, and what cannot be concluded from these claims.
Related reading: how to read email headers.
Compare two sets of headers
Technical headers remain in your browser. Nothing is transmitted, saved, or checked against a remote service. Compare header A (earlier or baseline) with header B (later or affected).
Export excludes raw headers, addresses, IPs and message identifiers. It may include visible sender domains and high-level authentication claims.
How the comparison works
Both header sets are parsed locally. They remain independent; results across different receiver identifiers or multiple conflicting hops are not collapsed into a single verdict. Compare authentic original headers and check the recipient-side message trace before changing DNS settings.
Read our methodology. Review AI email advice before changing DNS.