Question : Finalizing Migration From Exchange 2003 to Exchange 2010

We are in the process of finishing our move from Exchange 2003 to Exchange 2010.

The network before Exchange 2010 was a Single Windows Server 2003 R2 enterprise machine acting as the Domain Controller and Exchange 2003 server. On this machine Blackberry Enterprise Server was installed as well.

We added a Windows Server 2008 R2 Enterprise box and loaded Exchange 2010 on it. Currently all accept for 2 mailboxes have been moved from the 2003 box to the 2010 box. The last two are our BES users. We are discontinuing Blackberry after this move so we are curious on how to proceed.

Our thought is that we move the last two mailboxes. Uninstall BES, Reboot, Uninstall Exchange 2003, reboot and then are left with a plain old Windows Server 2003 Domain Controller. Any reason why this wouldn't work? or any other steps that must be completed?

Answer : Finalizing Migration From Exchange 2003 to Exchange 2010

Remove the users from the BES first, that will ask if you want to remove the Blackberry properties from the mailboxes.  Once you do that, you can move the users without any issues.

Is your BES working right now? We had trouble after installing 2010, our BES stopped communicating with the handhelds.  We were forced to upgrade BES from 4x to 5x Express.  Once we had BES5x installed, we used the Blackberry transporter to migrate the users from BES4 database to BES5 database.  After that, everything started behaving fine.

Anyhow, assuming your BES is actually working, you can remove the users from the BES, remove the BES properties from the mailbox, uninstall BES.  Any time after you remove the users from the bes, you can move the mailboxes to your 2010 server.

After you uninstall BES, you can perform the steps necessary to remove your final exchange 2003 server from the domain.