Clear Error Messages During MTA-STS Setup

If something stops your MTA-STS setup from completing, we now tell you what it is. The setup flow shows a clear message when a problem gets in the way, including CAA record issues that prevent the certificate from being issued. You can fix the cause and try again without guessing. If you see a CAA error, check that your domain's CAA records allow the certificate authority used for MTA-STS.