In SBS 2008 we automatically configure Content Filtering in Exchange 2007 to reject any e-mail that scores a spam confidence level of 7 or higher.
Get-ContentFilterConfig| fl scl*
SCLRejectThreshold : 7
SCLRejectEnabled : True
SCLDeleteThreshold : 9
SCLDeleteEnabled : False
SCLQuarantineThreshold : 9
SCLQuarantineEnabled : False
However, we do not configure the threshold for automatically moving suspect e-mails to the junk mail folder of a recipient. This setting is left with its default of higher than 8, basically having no effect whatsoever for inbound e-mail (as we are rejecting them at 7 anyways).