We are running ORF along with Mcafee's anti spam tools. ORF does a great job generally speaking but I have found recently that some email have been slipping through the cracks. Sexually explicit terms are making it through. A keyword filter would be easy enough to setup but I am unsure of how to create the regular expression.
For the most part I would like to create something that would state any word with C(any ascii character)CK at the beginning, middle or end of the word would be marked as spam.