Dovecot and Spamassassin
From Docunext Technology Wiki
Since I'm now using Dovecot's deliver LDA, my Courier Maildrop scripts for scanning mail with Spamassassin is not relevant.
From what I have read, the best way to handle this issue is integrating Spamassassin as a Postfix filter / milter and then using a Seive filter to put spam flagged emails into a junk / spam folder.