We are having a problem with coexistence of exchange 2003 and 2010. Emails are working from 2003 to 2010 but when emailing a user in the exchange 2003 environment mails just sit in the Unreachable queue and say there is no route to the mailbox database?
The routing group conenctor is there between our front end and back end 2003 servers. I have removed and recreated a couple of times but the problem still exists.
What can i try?