I am intending to implement W2K3 SBS in a single domain, with two sites and would like to provide fault tolerance for the Exchange 2003 implementation. The question I have is as follows: Can SBS Exchange can co exist with a secondary W2K3 box and a second Exchange Server in a different routing group with a routing group connector between them. I am aware that it can be done in a full W2K3 / E2K3 implementation. However, can it be done with SBS 2003 as I have been informed that SBS doesn't allow multiple routing groups. Can anyone help?