To monitor email for improper terms that HR might have a problem with, you can flag emails by content. You need to build a formula that will return a True for emails you want to flag. You can search for a string anywhere in the body field or search by words. Use @lowercase to make sure you find words regardless of capitalization.
To search anywhere which is faster:
NOTE: @contains will find the entries in the list anywhere including inside other words. The entry "cialis" will cause emails with the word "specialist" to be flagged. To prevent this enter it as " cialis ", with the spaces to indicate it's a word.
To search by word only use:
@explode(@text(@lowercase(body))) = "redneck":"babe":"cialis"
This will match on full words only.
NOTE: There is an issue with using this method on mime content (inbound html messages). Of you need to monitor inbound emails then use the first method for now.