About 75% of the SPAM I receive (unblocked by yahoo) has one or more headers that list "googleusercontent." I would like to have the ability to categorically block (i.e., delete, without going to spam, trash or anything else), any email message having this information appearing anywhere in its headers. Can Yahoo add that as an option or email filter capability? There are no valid emails I wish to receive having any sort of 'googleusercontent' affiliation. EACH of yahoo and myself would benefit by providing me with this capability.