What's your suggestions on how much ram, cpu etc...I need to procure hardware for the following upgrade: Client want to migrate from GroupWise to Exchange 2010They will want HA & DR There are about 750 accounts with only 500 or so active They have about 100 blackberry's There is no official mailbox limit. However they do monitor mail box sizes and request that data be archived so we can certainly look at setting a limit. They will use local storage. 11 offices but will go with centralized mail. i.e. - all servers located at HQWhat are your thoughts on the hardware needed, combining roles etc...My initial thought is:Combine all roles on two boxes for the HACombine all roles on one box for DR

Does your "DR" actually mean "site resilience"? If so, I guess not all servers will be located at the HQ. Not clear on that one so perhaps you can explain a bit more.Here are some links that will help you with sizing:Understanding Exchange Performancehttp://technet.microsoft.com/en-us/library/dd351192.aspxExchange 2010 Storage Calculatorhttp://msexchangeteam.com/archive/2009/11/09/453117.aspxNeil Hobson, Exchange MVP

Stating that all servers are at HQ is not entirely true. DR Server would be offsite.Does the number of servers look correct to you? i.e. - a total of three for their needs

Probably will work but you'll need a hardware load balancer to take care of CAS load balancing in that scenario. You'll want to follow the docs Neil posted and pay attention to the memory and CPU requiremnts in a multi-role config.Active Directory, 4th Edition - www.briandesmond.com/ad4/

Just for supplement, Exchange 2010 Deployment assistant:http://technet.microsoft.com/en-us/exdeploy2010/default.aspx#