I’ve changed the system procmail rules as follows:
DROPPRIVS=yes MAILDIR=$HOME/mail INCLUDERC=/etc/mail/spamassassin/spamassassin-default.rc :0: * ? test ! -f $HOME/.procmailrc * ^X-Spam-Status: Yes spam
The reason for this change is so the system procmail rules won’t put mail scored as spam in a spam folder with giving user procmail rules a chance to override.
If you have a .procmailrc file and want mail scored as spam to go into a spam folder, then you need a rule like this:
:0: * ^X-Spam-Status: Yes spam
If you’d rather have mail that scores as spam discarded, then you need a rule like this:
:0: * ^X-Spam-Status: Yes /dev/null
If you have no .profmailrc file, then the default behavior is still to put mail marked as spam in your spam folder.