Determining the Scalability of Combined CAS and Hub Roles in Exchange 2007http://blogs.technet.com/jkruse/archive/2009/06/05/determining-the-scalability-of-combined-cas-and-hub-roles-in-exchange-2007.aspxBill Thompson has written a great whitepaper on considerations for Exchange 2007 servers running both the CAS and Hub roles. This white paper provides information about the scalability of computers running Microsoft Exchange Server 2007 with the Clienten-USCommunityServer 2.1 SP1 (Build: 61025.2)