Mail is only scanned once, on the way into the system. It's not scanned during distribution and delivery.
I have created an account to receive all spams and disabled filtering on it. I have also set up the "qpsmtpd Bcc" to archive all email in and out. I'm receiving a second copy of each spam in the spamboss mailbox which I assume comes from the filtering on the bccuser account. So it seems mail is being scanned more than just on the way in.
I've also created "/etc/e-smith/templates-custom/var/service/qpsmtpd/config/peers/local/70spamassassin" to scan email coming in on the lan. Could this be the cause of the second spam copy ?
The second spam copy isn't causing any problems but I would like to understand it on my way toward creating a feature request and suggesting documentation updates in the bug tracker.