So I ran into this issue I needed to find out if SP2 was installed on a Exchange 2003 Server I was working on for a client. The issue was this server was a SBS (Small Business Server Edition) So when you clicked Help>About on Exchange Manager it only would give you 6.5.7638.1 and nothing about SP2 or anything.. After some research I found the following and figured I would share it.
Exchange 2003
6.5.6944 = Exchange 2003
6.5.7226 = Exchange 2003 SP1
6.5.7638 = Exchange 2003 SP2
6.5.7638.1 = Exchange 2003 SP2 + some Exchange Patches Installed
Exchange 2007
8.0.685.24 or 8.0.685.25 = Exchange 2007
8.1.0240.006 = Exchange 2007 SP1







