About the Header Analyzer
Email headers record every server a message passed through, with timestamps, plus the authentication results the receiver calculated. The analyzer turns that raw text into a clear timeline and highlights slow hops and failed checks.
To get headers: in Gmail open the message and choose Show original; in Outlook open File → Properties → Internet headers; in Apple Mail choose View → Message → All Headers.
How to get email headers
Gmail: open the message → ⋮ → Show original. Outlook: File → Properties → Internet headers. Apple Mail: View → Message → All Headers. Paste the complete original to let us verify DKIM signatures too.