We have an Exchange 2007 organization with 7 CAS,MB & HT servers. Planning to deploy only exchange 2010 CAS server for GAL sync with Federation Gateway by extending the schema. My concern is : 1. If a new 2010 CAS is added with cooexistence Who will handle MAPI requests ( exchange 2010 CAS or 2007 Mailbox server) 2. We have only exchange 2007 CAS within the organization ( No internet facing servers) Will all non-mapi requests are routed to 2010 CAS box or legacy 2007 CAS servers. As per my knowledge when we add CAS 2010 box SCP object is updated with new autodiscover service which is routed to 2010 CAS box. Will the existing legacy CAS servers idle & all the load is handled by new 2010. Do we need to do DNS changes to make use of Legacy CAS servers. Please share ur comments.

Hi Martina, Actually i have opened a thread in General discussion, Later identified all architecture related queries has to be opened in Deploy section. I am sorry for opening one more thread.Ahmed Ali