Spamassassin, Dovecot and Postfix: Move spam to folder

master.cf

smtp      inet  n       -       -       -       -       smtpd          -o content_filter=spamassassin
spamassassin unix -     n   n   -   -   pipe      flags=DROhu user=vmail:vmail argv=/usr/bin/spamc -f -e      /usr/lib/dovecot/deliver -f ${sender} -d ${user}@${nexthop}
 master.cf
smtp      inet  n       -       -       -       -       smtpd          -o content_filter=spamassassin
spamassassin unix -     n   n   -   -   pipe      flags=DROhu user=vmail:vmail argv=/usr/bin/spamc -f -e      /usr/lib/dovecot/deliver -f ${sender} -d ${user}@${nexthop}