Our environment consists of a windows network with two Windows 2003 Domain 32 bit and one Windows 2003 Domain 64bit controllers. There is only one Exchange Server and it is an Exchange 2003 32 bit version. We have acquired a new server with Windows 2008 64 bit to host a second exchange server.
As a Disaster/Recovery plan, we want to introduce a second Exchange Server on the network and share the email accounts to do load balancing.
When we attempted to install Exchange 2003 to the new Windows 2008 64-bit server before upgrading to Exchange 2010 as a safer option, it failed; It seems that Exchange 2003 cannot be installed on Windows 2008 64 bit server.
The questions are:
If we have to install Exchange 2010 on the new windows 2008 server, Can it coexist with our Exchange 2003 server and in a Windows 2003 domain? If so, what would be the sequence of steps to achieve this?
If NO!!, what would be the best upgrade path. Would we have to also upgrade the Windows 2003 domain?