I'm looking for experts on the topic of routing groups between legacy Exchange 2003 and a coexisting Exchange 2010.
(Still) works: I am able to both send and receive mail external domains on the internet from both servers. Also I have no trouble sending from 2003 to 2010.
Problem: I am unable to send any mail from mailboxes on 2010 to 2003.
These emails stick in the message queue.
Detail: the external email domain is different from the internal domain name.
I would really like some help with this issue. Anyone?
Thanx in advance!