Filter feature request

[timf]

Could "entire message" be changed to mean "entire message omitting base64 blocks" (which is how I think it used to be in the old Mailwasher). I could not work out how some of my good mail was getting marked for detetion until I found "hgH" and "<expletive deleted>" in the middle of an attachment encoded base64, both of which are in my regex set of exclusion strings.