EmailVerify.NET - Validates an e-mail address up to the catch-all level and display the eventual failure reason script in Windows PowerShell
This command validates the e-mail address johndoe@example.com up to the CatchAll level and, should it fails, it tells what is the cause of the failure.
$validationResult = (Verify-EmailAddress 'johndoe@example.com' CatchAll)
if ($validationResult.IsSuccess -eq $false) {
$validationResult.Failure
}