Free email-authentication toolkit
Paste the full headers of a message and get the DMARC verdict, why it came out that way, the delivery path and every header — no signup, no backend.
Paste the full headers of a message — Gmail's Show original, Outlook's Message source. You will get the DMARC verdict, why it came out that way, the delivery path and every header.
The basics, briefly
Gmail: open the message → ⋮ → Show original. Outlook / Microsoft 365: open the message → File → Properties → Internet headers. Apple Mail: View → Message → All Headers. Copy everything from the top down to the first blank line.
No. The analysis runs entirely in your browser; nothing is sent to a server. The parser stops at the first blank line, so the message body is never read at all.
DMARC needs more than a pass: the domain that passed has to align with the domain in the From: header. A message sent through a provider often passes SPF for the provider's own domain, which is not yours. Read more: DMARC alignment explained.
It means this header does not contain the receiver's own verdict for one of the two checks, and we will not guess. A DKIM-Signature header shows a signature exists but not whether it verified — only the receiving server can say that, in Authentication-Results.