Here is my situation. Thanks in advance for any help you can offer!
We have an existing BES (4.06) running on a Windows 2000 Server box that is a member server of a Windows NT 4 domain.
We have a Windows 2003 domain environment.
We have an Exchange 5.5 server on our domain that currently hosts email for all BES users.
We have an Exchage 2K3 server on our domain to which we are attempting to migrate all BES users.
We have a new server set aside on the 2K3 network to become the new BES.
Our W2K3 domain has a two way trust relationship with the NT 4 domain where the current BES lives.
Our goal is to perform a knife edge cutover, in order to migrate the users from 5.5 to 2K3, and move the BES users from the current BES to a new BES on the 2K3 domain. RIM technical support initially advised us that this would not be a problem, and that all we would need to do is install the 2K3 version of ESM on the current BES, and we would then be able to migrate the users mailboxes, and the BES database.
Our problem: We are unable to install the 2K3 version of ESM onto the current BES. It fails, because it requires communication with a 2K/2K3 domain controller.
We do not have the option of promoting the existing BES, or of migrating the entire server to our domain. We strictly want to cutover the users, then migrate their mailboxes to 2K3, at which time the existing BES and the 5.5 server will be decomissioned.