We are getting errors when emailing just certain domains (not all) and this just started happening recently. After reading 100 articles online and trying about everything I'm hoping someone can give me another idea.
I already flushed dns, restarted the server, restarted DNS, restarted SMTP etc...
THis is the returned error we get from certain emails:
The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry. If that fails, contact your administrator.
What could it be? Is there somethign I should change on the Exchange Server or is this a problem on the DNS server?