I have a sound understanding of Exchange server 2003 but skipped a whole generation by never really testing/playing with Exchange 2007. However, I recently undertook a server migration where I deployed Exchange 2010 and decommissioned an old Exchange 2003 server. I replaced the server like-for-like and so the Exchange 2010 server was also a single server operating in the domain.
Before hand, I decided to try a deployment on a test server just to see if I had any issues. The server is a single box that is also a Domain Controller. For testing purposes I also installed Exchange 2010 onto the same server. Initial installation and configuration was a breeze and I was soon sending and receiving email internally and externally. Upon investigation of some of the more granular Exchange configuration I soon had an issue when I tried to enable Recipient Filtering, there was simply no option to do so.