This is our current setup, I have 1 CAS 2007 server and 1 Mail 2007server with few mail boxes for the testing purposes in a mixed environment (exchange2003). I have tested mail for the 2007and everything seems to be in working order. Now I wanted to setup a SCR for the DR site and so I have created new exchange2007 server and followed all the steps as far as the same hardware and same disk drives and folders, and SCR function seems to be working also (test-replicationhealth). My question is what about the CAS server? 1: Do I need to create another CAS server for the DR site? 2: Do I just install and setup as if it is another exchange server? 3: Do I need to do anything different on this server? If anybody can show me step by step guide to how to set up and test would be greatly appreciated.