This morning the exchange server at my office stopped sending email. It will receive email but won't send. The queue showed 6000+ emails. After performing various troubleshooting techniques and rebooting the server it now shows 400+. On each of the emails in the queue it indicates that it could not create a connection with the destination server. I tried to do an NSLOOKUP on a couple and it came up empty. No changes that I know of have occurred. I'm thinking this may be DNS related (my weak area). Anyone have any suggestions?