We have an Exchange 2000 server, on which the BESAdmin account resides. We also have an Exchange 2003 server and have installed an Exchange 2007 server. We are using BES 4.1.4.12 and have installed the proper cdo's and MAPi for Exchange 2007. Moved a BES user over to the EX2007 server and it could not receive emails.

Do I need to move the BESAdmin account to the Exchange 2007 server first?

Should I set the MAPI profile to the Ex2007 server. and do I have to move the account to that server first?

If I set the MAPI profile to the EX2007 server, are the BB users on the other servers still going to be able to communicate with it on their blackberries?
Public folders are installed on a stand-alone Ex2007 server.

All the appropriate rights have been assigned to the BESAdmin account for EX2007 as well.