Implementation:

  • Login on server as root
  • Install spamassassin through aptitude
  • In /etc/default/spamassassin:
Set ENABLED=1
  • Add/uncomment in /etc/spamassassin/local.cf:
rewrite_header Subject *****SPAM*****
report_safe 0
  • In /etc/postfix/master.cf:
smtp      inet  n       -       -       -       -       smtpd
  -o content_filter=spamassassin

spamassassin unix -     n       n       -       -       pipe
  user=debian-spamd argv=/usr/bin/spamc -f -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}
  • Restart services
service spamassassin start
service postfix reload

Verification:

Email sent to server with body XJS*C4JDBQADN1.NSBN3*2IDNEN*GTUBE-STANDARD-ANTI-UBE-TEST-EMAIL*C.34X should have subject rewritten to ****SPAM**** $header