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Email Headers

Metadata attached to emails that shows routing information, authentication results, and delivery path.

Email SecurityAlso called: "email metadata", "message headers"

Email headers reveal the true origin and path of a message, crucial for investigating phishing and spam.

Key headers

  • From/Reply-To: Sender addresses (can be spoofed).
  • Received: Each mail server that handled the message.
  • Return-Path: Where bounces should go.
  • Authentication-Results: SPF, DKIM, DMARC verification outcomes.
  • X-Originating-IP: Sender's IP address (if available).

Phishing detection

  • Check Received headers for suspicious origins.
  • Verify SPF/DKIM/DMARC authentication passed.
  • Compare From address with Return-Path for mismatches.
  • Look for forged Received headers (inspect timestamps).