Outlook the will get the following certificate error when you first startup.
To resolve this issue first make sure this is indeed the issue, let’s check that the URLs are incorrect. To do so run the following command.
Get-ClientAccessServer |fl identity,autodiscoverserviceinternaluri
If it lists any url that does not match the SANs on your certificate then we need to change those urls. We do so with the following command.
Set-ClientAccessServer -Identity OLD_SERVER -AutodiscoverServiceInternalUri correct_Autodiscover_URL
If outlook still popup the error of the mismatch, delete email profile and recreate it.