I think it would be very helpful if Mozilla supported NoCeM notices. NoCeM is a system designed for recommending that certain messages be marked as read, deleted, or highlighted. It is entirely voluntary, and only notices from senders the user trusts are used. Digital signatures are used for security. It is much less prone to abuse than third-party cancel messages. The NoCeM home page is http://www.cm.org/ , and O'Reilly's "Stopping Spam" also goes into the topic. I have filed an RFE for it in bugzilla. http://bugzilla.mozilla.org/show_bug.cgi?id=73075
