I am currently in the process of moving to Exchange 2010 from 2003. I have a single server and a single domain. My question is, I would like to install the Exchange 2010 software and then in a couple of days actually cut over to have mail flowing though the 2010 server. I have quite of bit of mailbox data to move and will actually be doing that overnight over some time.
But I just wanted to be sure that I can install the software on the new Exchange box and not have it disrupt email flow to the 2003 server until I start to configure the 2010 roles (they would however be installed)