I have an Exchange 2003 Enterprise organization which I am trying to update to Exchange 2010. I have the Exchange 2010 servers built and was able to move over two accounts from Exchange 2003 to Exchange 2010 (all in the same organization and domain). The problem I am having is that once one of the mailboxes is moved to Exchange 2010 from Exchange 2003, it can send e-mail to an Exchange 2003 mailbox in the same organization, but it cannot receive e-mail from an Exchange 2003 account.
I can also send e-mail to the Internet from the moved Exchange 2010 mailbox, but cannot receive mail from an internet account back into Exchange 2010.
Can anyone offer any insight?
Thanks in advance.