No, rules don't have a "history" and rules for one newsgroup do not check
through all the read messages for every other newsgroup. And you wouldn't want
them to: You _could_ I suppose, write an AppleScript to do that, but can you
imagine how it would slow things down to a standstill if every single message
had to be checked against all the read messages for very other newsgroup you
subscribed to, just in case there was a match?
