Deleting e-mails using kmail filter

Hi,

I wonder if it is possible in kmail to immediately delete e-mails, not moving 
them into some trash or so, using the filter. I would like to use this for 
example for e-mails having more than 20 spamassassin points, which I would 
like to delelte without further checking (I trust SA that much!).

What I do now, is having a separate spam folder called "ReallySpam", moving 
the respective e-mails there inside using filters and setting the time to keep 
e-mails in this folder to 1 day. But of course, this is just a work-around, if 
I could delete emails directly, it would be better.

Any ideas?

Johannes