Email Header Analyzer

Why analyze email headers?

Raw email headers show the path a message took, Authentication-Results (SPF, DKIM, DMARC), and often spam scores. Use this header analyzer to debug bounces, trace spoofing, or verify authentication.

What to look for

Received lines show each hop from sender to receiver; the first is usually your server, the last the recipient's. Authentication-Results (added by the receiving server) tells you whether SPF, DKIM, and DMARC passed or failed. From, To, Subject, and Date are the usual envelope and display fields. Return-Path is where bounces go. Headers are not stored here; paste from "View source" or "Show original" in your mail client.

Quick tips

• Look for Received lines to see each hop; the first is usually your server, the last the recipient’s.
• Authentication-Results tells you if SPF/DKIM/DMARC passed or failed at the receiving server.
• Headers are not stored here; paste from “View source” or “Show original” in your mail client.

Things to consider

Headers can be forged by earlier hops; trust the receiving server’s Authentication-Results. Large attachments or inline content aren’t in the header — only metadata and routing.