procmail and spambouncer

[Gawain Reifsnyder]

I want to implement spam filtering for several users. My ISP recently 
installed qmail and vpopmail on our colocated Yellow Dog Linux 
server. The machine already has procmail 3.14 installed, although 
I've never used it. I installed spambouncer 
<http://www.spambouncer.org> (which uses procmail) according to the 
directions, but it doesn't seem to be doing anything. Are there any 
known gotchas with this setup?

Gawain