This is very impressive in itself but what is the practical use?
I mean you probably could get (almost) the same result with much less work. For instance, &quot;Academic&quot; is every mail send from an .edu domain, &quot;financial&quot; is everything that comes from your bank, &quot;personal&quot; mails come from a sender that is in your personal address book and so on.<p>In short, there are &quot;good enough&quot; rules that require much less processing.