Some organizations use the built-in anti-spam feature in Exchange 2007 and 2010. http://technet.microsoft.com/en-us/library/aa997658(v=exchg.141).aspx.
Content Filter engine is using definitions created by Microsoft and in an ideal world they are downloaded, approved and installed with help of windows update, but for many reason this is not always possible.
I created a small vbscript that uses windows update to search for only Exchange standard antispam updates and automatically install them without doing anything with other updates.
WU_Exchange_AntiSpam.vbs script can easily be scheduled to run with task scheduler.
If you run this script manually, use the cscript engine because some text is written and looks better if you don’t use the wscript engine.