Today we are an Exchange 2003 shop (only 350 mailboxes) but shortly we'll be migrating to Exchange 2007. My question pertains to DR. We have another data center today with WAN connectivity and would like to set up replication of our mailbox databases once we go to Exchange 2007. I was wondering if someone could reply back with some real time experience on designing and deploying the solution. Is it safe to assume that SCR will need to be used? How would the design look? I appreciate any feedback.

Your 2 main options are: 1. Implement SCR to a server (or another cluster) at the DR site. 2. Implement stretched CCR across the two sites. The second option depends more on factors such as the bandwidth and latency of the link since RPC comms comes into the equation, plus the CCR cluster nodes would need to be on the same subnet if using W2K3 as the operating system. Plenty to think about with that one. Mind you, you'd still need to look at the bandwidth and latency when implementing SCR. Step back first and decide if the DR site is used for DR, or whether you'd also consider it a live site. If DR only, SCR is likely the best fit since the DR site only becomes active as and when you choose it to be that way. Also, do you want high availability as well as site resilience? SCR is a site resilience option, whereas CCR is a high availability option. If you now say you want both, a common configuration is a CCR cluster at your production data center, with SCR to a standby cluster or single server at the DR site. Plenty to think about.