For some odd reason Exchange 2003 won't send out emails ending with a .gov extension, they just stay stuck in the queue. Everything else goes out just fine. This started a few weeks ago. I haven't made any changes, but it does the regular windows updates.
I use Sendlabs SMTP to send out email because it is lot easier than dealing with AT&T's constantly shifting rules with spam, it is running on Windows Server 2003 behind a Sonicwall TZ190 firewall.
I have cleared cached DNS stuff on DNS server and restarted the machine, still .gov emails are still getting stuck then eventually sending back an error saying "No route was found for the recipient server."
How do I fix this?