Email authentication tester

Send a real message and see what happened to it: SPF for the address that actually connected, every DKIM signature, and whether either aligned with your From address — which is what decides DMARC, and the part most checkers skip.

New to this? What check@auth.mxio.io is and how to read the reply →

or just email check@auth.mxio.io from whatever you want to test.

What you get back

Sample data

A report for a made-up domain, so you can see the shape of the answer before you send anything. Yours names your own records, and adds a live check of your domain underneath.