Paste raw email headers to trace delivery path, check SPF/DKIM/DMARC authentication, and diagnose routing issues.
In Gmail: click the three dots menu on an email and select “Show original”. In Outlook: open the email, click File → Properties. In Apple Mail: View → Message → All Headers. Copy the full header text and paste it above.
Email headers reveal the sender's server, the delivery path (hops), authentication results (SPF, DKIM, DMARC), the sending application, timestamps, and potential signs of spoofing or relay issues.
SPF verifies the sender's IP is authorized, DKIM adds a cryptographic signature to verify the email wasn't modified in transit, and DMARC ties SPF and DKIM together with a policy for handling authentication failures.