Check a message
Is this email really from who it says?
Paste the top part of it. We will say how it was sent, whether the address was really used, and what to do next. It takes a second, nothing is stored, and there is no account.
First, who are you?
The evidence is the same either way. The advice is not: one of you needs to know whether to pay an invoice this afternoon, and the other can have a domain taken down.
You were sent it. We will tell you whether to trust it and what to do about it.
Paste the top part
The headers are what matter, and forwarding usually strips them. In Gmail: open the message, the three dots, Show original, then Copy to clipboard. In Outlook: File → Properties and copy the internet headers. Gmail's little summary box at the top, the one listing SPF, DKIM and DMARC, is enough on its own: paste that and we can read it. The headers are plenty either way, and we never need what the message said. If all you have is the forwarded text, paste that and we will say what we can. Delete your own address out of it first if you would rather, along with anything else you do not want to send us. We only read the part that says who it came from, so taking your own name off it changes nothing about the answer.
The four ways it gets done
Only the first one shows up in a business's own email reports. The other three are visible to the person who received the message and to nobody else, which is why this page exists and why it is free.
They send as you@yourbusiness.com. Enforcement stops this one dead: the message is refused before anyone sees it.
Your reports see this.
One letter different, or a different ending. Your domain is never touched, so nothing of yours records it. A registrar will act on a factual report.
Only the recipient sees this.
Your name in the part people read, sent from an ordinary Gmail, or through a platform like Patreon, Substack or Etsy where anybody can open an account in any name. Platform mail passes every check there is, because the platform really is sending it. No setting on your domain can prevent either. Telling your customers is what works.
Only the recipient sees this.
Yours, or somebody else's in the same conversation. It passes every check because it is genuine. The reply address is often the giveaway.
Only the recipient sees this.