Free Email Header Analyzer

Paste the headers of an email. See whether SPF, DKIM and DMARC passed, whether they line up with the From domain, and where the message sat waiting. It runs in your browser, so nothing you paste leaves your device.

In Gmail: open the message, click the three dots, then Show original. Copy the whole header block.

Reading email headers

The three headers that matter most

Authentication-Results is the receiving server's verdict on SPF, DKIM and DMARC. It is the fastest way to see why a message was trusted or not. DKIM-Signature shows which domain signed the message and with which selector. Received headers trace every server the message passed through, with a timestamp at each one.

How do I find the full headers of an email?

In Gmail, open the message, click the three dots and choose Show original. In Outlook on the web, open the message, then the three dots, View, View message source. In Apple Mail, choose View, Message, All Headers. Copy everything above the message body.

Why did my email go to spam when SPF, DKIM and DMARC all passed?

Authentication proves who sent the message. It does not prove anyone wanted it. Spam placement then comes down to reputation and engagement: complaint rates, sending to old or unengaged addresses, sudden volume jumps, and content. Passing all three is the entry ticket, not the whole test.

What does DKIM alignment mean?

For DKIM to count toward DMARC, the domain in the signature (d=) has to match the domain in your From address, or share its organizational domain. A message signed only by your email provider passes DKIM but fails alignment.

Why are there so many Received headers?

Every server that handles the message adds one on top. Read them from the bottom up to follow the path from sender to recipient. The analyzer does this for you and shows the delay at each hop.

Are my headers sent to your server?

No. The analyzer runs entirely in your browser. Headers contain addresses and IP information, so nothing you paste leaves your device.

Found a failure? Check the records behind it with the DMARC checker, the SPF checker and the DKIM checker.

Own your email platform

Broadcast is self-hosted email marketing software. It adds one-click unsubscribe headers for you and watches your DNS records. Pay once, run it on your own server.

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