I am in the process of confguring a VM for Exchange 2010 which will host all roles except the UM. It will host about 200 mailboxes. I am trying to determine how much memory and how many CPU's to assign to this VM. Any thoughts? I have a HP DL360 G7 with 2 Quad core E5640 processors and 24GB of memory. The only other VM I plan on installing on this server is a BES.