FPE use cloudmark engine to analyze each email and stamp it with a SCL. Please check the content filtering as per this article:
http://technet.microsoft.com/en-us/library/dd639396.aspx, if you find some missed spam or false positives, just send the original e-mail message for analysis to:
For false negatives: Forefrontemail@example.com
For false positives: Forefrontfirstname.lastname@example.org
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