3300 spam messages rejected on mail RCPT in the last six days. 550 per day.
You can see elsewhere on this site of how I installed Simscan with Qmail. Adding spam checking at the mail border with Simscan is was simply a matter of apt-getting SpamAssassian, recompiling Simscan by changing from
./configure --enable-workdir=/var/spool/simscan/ --enable-received=y
./configure --enable-workdir=/var/spool/simscan/ --enable-received=y --enable-attach --enable-spam --enable-spam-hits=5
and building a good copus of spam messages. Combined with a centralised bayes token file:
$ cat /etc/spamassassin/local.cf #... bayes_path /var/spool/spamassassin/bayes bayes_file_mode 0666
At the moment I’m added spam messages manually with sa-learn, but I expect I will setup a cron job in due course which checks an IMAP folder. Plus with this method the problem with false positives is much less, as senders of non-spam messages will received a definite non-delivery message. They are more likely to catch this than for me to notice them amongst 550 pieces of spam.