Problem with kmail Filter

[Philippe Merlin]

Hello,
I use Kmail 1.5.4 in kde 3.1.4  French and all the Pop Filter i configure does 
not work: My mail box is actually spammed with messages of 150 Ko and if i 
filter with size it does'nt work. Filter on subject or from  does not work.
Happily someone tell me about software "mailfilter" and it work fine.
May i have help to configure filter on Kde.
Thank you.
Philou75