All of the sudden after about midnight last night all outgoing mail is stuck in our queue. Nothing was changed on the receive and send connectors. When going through telnet on the mail server I am getting 550 5.7.1 unable to relay, this is to external addresses. We relay all mail via smarthost and I have confirmed with them that everything is fine on their end.
I have checked under "Server Configuration" mail server properties and the mail server is set to use the NIC's DNS for external DNS. I really do not know where to go from here.