I have been trying to get vpopmail to handle prelining to Spamassassin _AND_ setup vacation autoresponds on a handful of low-volume virtual domains. (qmail,procmail, SA, vpopmail, qmailadmin).
I've had the dot-qmail files working, but I had somehow created an extra layer of them, and qmailadin made things even more wonky.
This little tutorial made it clear how and where the procmailrc needed to go for each virtual domain, along with just how the dot-qmail files should work.
Simple scripts, and I got this going on my first of six domains in about 35 minutes (worked first try! no typos!)
Thanks for a good writeup,