We are a small Church with about 20 users. I have finally gotten the OK to upgrade from Server and Exchange 2003. Budget is tight. I have just enough for OS upgrade and additional memory for the servers. Currently we have two servers. I am looking for advice as to which versions of Server and Exchange would be recommended. Our users are on Windows 7 pro with Outlook 2010. I would like to give their mobile devices access to email as well. A few users are working remotely via VPN when travelling.