8.11 Reverse Scoring

If you want to keep just articles that have ‘Sex with Emacs’ in the subject header, and expunge all other articles, you could put something like this in your score file:

(("subject"
  ("Sex with Emacs" 2))
 (mark 1)
 (expunge 1))

So, you raise all articles that match ‘Sex with Emacs’ and mark the rest as read, and expunge them to boot.