How to check Microsoft Exchange Server Service Pack level?
Right-click STORE.EXE in Microsoft Exchange Server BIN diretory (by default C:\Program Files\Exchsrvr\BIN\) and select Properties. The Version tab has the Microsoft Exchange Server version as well as the Service Pack level. In addition, you can also check the Service Pack the following: Open Exchange System Manager (Start / Programs / Microsoft Exchange / System Manager) and go to under servers view and right-click properties of the Exchange Server object. In General view you can see Service Pack level.