EmailXaminer - How to Filter Out Email with Disclaimers

What is the correct procedure for filtering out email that has disclaimers from being sampled? For instance, a disclaimer may have key words that is being flagged via a lexicon, so this email will be subject for review. The client would like to exclude keywords from all types of disclaimers, and only have the email up for review if those words are found outside of the disclaimer. I believe that I need to set up a lexicon and then use it as an exclusion, but would like to get other people's experience and suggestions.

Thanks in advance.