Wouldn't a cron job be easier? Like at least a few others, I have "should be spam" and "not spam" maildirs, and a cron job set up (in my case, hourly) to scan those directories with sa-learn (and in my case, delete the messages in the directories when finished).

It'd fix your 6-second-move issue, and a master script to scan the folders for every user on the system wouldn't be hard to set up.

However, I don't see how this addresses the issue of SpamAssassin not being able to get at the "true" homedir of courier's virtual users.

-Chris