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Analysis

Email header analyzer

Analyze the headers of a received email: the route across servers with delays, SPF, DKIM and DMARC results, alignment and spam score.

We only analyze the headers for this display and don't store them.

How to find the headers

  • Gmail: open the email → three-dot menu → “Show original” → “Copy to clipboard”.
  • Outlook (web): open the email → three-dot menu → “View” → “View message details”.
  • Outlook (desktop): double-click to open the email → File → Properties → “Internet headers” field.
  • Thunderbird: open the email → View → Message Source (Ctrl+U).
  • GMX / WEB.DE: open the email → three-dot menu → “Show source”.

You can also paste the whole email – only the headers up to the first blank line are analyzed. Want to check an email before sending it? That's what the email test is for.

FAQ

How do I read an email header?

Copy the full headers from your mail client (in Gmail “Show original”, in Outlook “Properties”) into the field. We show the route across all servers with delays and the SPF, DKIM and DMARC results in plain language.

How can I tell why an email landed in spam?

Look at the Authentication-Results line: if it says spf=fail, dkim=fail or dmarc=fail, the sender's setup is usually the cause. Spam scores such as X-Spam-Score or Microsoft's SCL also show how the filter rated the content.

What does alignment mean in DMARC?

DMARC requires the domain in the visible From address to match the domain confirmed by SPF or DKIM. If a sending service only signs with its own domain, DKIM passes but DMARC fails.

Are the pasted headers stored?

No. The headers are only processed for this one analysis and are not stored.