I have an application server that sends email out using relay on my exchange 2003 server. We specifically allow the IP address of the application server to relay off our exchage server. We also use a barracuda spam/email server. Everything was working fine. I changed the IP address of our application server to a different subnet. I modified the smtp connector to reflect the new IP address.
NOW I can send email from my application server to internal address. I CANT send outboud to external addresses like yahoo.com.