Spam… who does not get it in INBOX.. I get a lot of spam each day — one day I got 70MiB of spam and because of that I started to use bogofilter. It does his work well — I trained it with over 1GiB of spam from my collection and it rarely gives me ‘false positives’.
But KMail which I used as MUA run bogofilter synchronously so when I try to get mail I have it frozen for few minutes. Maybe it’s time to switch to old times scheme and use fetchmail+maildrop to fetch/filter mails…