We are in the process of migrating a client from Exchange 2003 to 2010. We've configured a new FQDN for the new server as well as a new SSL cert. The server is working and can send mail.
However, the MX record is still pointed at the old FQDN of the Exchange 2003 server and mail destined for a user on the 2010 server simply gets stuck in the Local Delivery queue of the old server.
The two server will need to coexist for a couple of weeks as we migrate users. Any thoughts on how to proceed would be welcome...