Email header analyzer
Paste the raw headers from any email to read its authentication story: the SPF, DKIM and DMARC results, whether they align with the From: address, and exactly what each verdict means. Runs entirely in your browser.
Runs entirely in your browser. Your headers never leave your device.
Frequently asked questions
How do I get the raw email headers?
In Gmail, open the message, click the three-dot menu and choose 'Show original'. In Apple Mail, use View → Message → All Headers. In Outlook, open the message and go to File → Properties, then copy the Internet headers. Paste the whole block here, everything above the first blank line.
What's the difference between authentication and alignment?
Authentication asks 'did SPF or DKIM verify?' Alignment asks 'does the verified domain match the visible From: address?' DMARC only counts a mechanism when it does both. That's why a message can show spf=pass but still fail DMARC. The SPF domain didn't align with From:.
Why does SPF pass but not align?
Most email services send with a Return-Path on their own subdomain (like [email protected]), so SPF authenticates that domain. If it doesn't share your From: organizational domain, SPF won't align, and DKIM alignment has to carry DMARC instead. This is normal, as long as DKIM is aligned.
Is my email private?
Yes. The headers are parsed entirely in your browser with JavaScript. Nothing is uploaded or sent to a server. You can verify this by going offline and running the tool.