I am having trouble getting mail to flow from Exchange 2003 to Exchange 2007 in a co-existing state. I have mail flowing from 07 to 03 and in and out of the enviroment, but can't get mail flowing from 03 to 07.
In transition state (exch 2003 and 2007 co-existing), mail from 2003 mailboxes to the 2003 mailboxes is queuing up in the queue related to the intra RDC connector. Tried re-creating the connector multiple times. Can telnet from the 2003 box to the 2007 box and successfully send mail using HELO commands.