From Jon's Wiki
Stuff about sieve.
Using dovecot, set up for Maildir format in ~/Maildir directory. DSpam uses procmail to deliver, so user ~/.procmailrc should have:
PATH=/bin:/usr/bin:/usr/sbin MAILDIR=$HOME/Maildir/ DEFAULT=$MAILDIR/ DELIVER="/usr/lib/dovecot/deliver -d $LOGNAME" # deliver to INBOX and stop :0 w | $DELIVER
Then set up dovecot to use sieve:
# /etc/dovecot/conf.d/15-lda.conf protocol lda { mail_plugins = $mail_plugins sieve }
# /etc/dovecot/conf.d/90-sieve.conf plugin { sieve = file:~/sieve;active=~/.dovecot.sieve sieve_user_log = ~/.dovecot.sieve.log }