Couple questions on building Content Filters.

1.)  Is it possible to content-filter on blank subject line?  I don't see an option for "Subject" --> "is blank".  A customer is receiving a lot of spam with blank subjects and would like to send them to the Junk folder based on blank subject line.

2.)  Is it possible to force the content filter to NOT evaluate a filtered word as a substring?  For example, a customer created a keyword block filter that includes the word "sex".  But those 3 letters, are ALSO being used to catch legitimate words like "Sussex" and "Essex", as well as H.R. emails dealing with "sexual harassment".