By default these versions of Microsoft Exchange have a limitation of 16GB per Database, if you have problems trying to mount the database you have to make sure you defrag it then do this reghack to increase the size by 1GB temporarily.
- Click Start, click Run, and then type regedit.exe. Locate the following key in the registry:
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\NameOfServer\Private-
- Make a DWORD Value Entry called: “Temporary DB Size Limit Extension”
- Change the hex value from 0 to 1.