Free tool · Analyze
Email header analyzer
Paste the headers of an email to see the path it took, how long each hop took, and the SPF, DKIM and DMARC results the receiving server recorded. It runs in your browser; nothing is uploaded.
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Getting the headers
Gmail: open the message, click the three dots, then Show original. Outlook: open the message, then File › Properties (desktop) or the three dots › View › View message source (web). Apple Mail: View › Message › All Headers.
Copy everything above the first blank line and paste it here.
Go deeper: SPF, DKIM and DMARC for transactional email
Questions
How do I read email headers?
Read Received headers from the bottom up: the bottom one is where the message started, the top one is the final server. Authentication-Results, added by the receiver, records whether SPF, DKIM and DMARC passed.
Why was my email delayed?
Compare the timestamps on consecutive Received headers. A long gap between two hops shows which server held the message, often because of greylisting, a queue, or a retry after a temporary error.
Are my headers sent anywhere?
No. The analyzer runs entirely in your browser.