I have previously been using qmail with qmail-scanner, which i had setup to show all spam ratings in the logs (/var/spool/qmailscan/qmail-queue.log) . like this :
Sat, 16 May 2009 12:37:57 EST:4462: SA: REPORT hits = 15.1/4.0
0.0 HTML_MESSAGE BODY: HTML included in message
1.8 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars
1.5 RAZOR2_CF_RANGE_E8_51_100 Razor2 gives engine 8 confidence level
1.5 RAZOR2_CF_RANGE_E4_51_100 Razor2 gives engine 4 confidence level
3.5 RAZOR2_CHECK Listed in Razor2 (http://razor.sf.net/
0.5 RAZOR2_CF_RANGE_51_100 Razor2 gives confidence level above 50%
3.5 DCC_CHECK Listed in DCC (http://rhyolite.com/anti-spam/dcc/
0.0 DIGEST_MULTIPLE Message hits more than one network digest check
2.1 DRUGS_ERECTILE_OBFU Obfuscated reference to an erectile drug
0.6 DRUGS_ERECTILE Refers to an erectile drug
Sat, 16 May 2009 12:37:57 EST:4462: SA: yup, this smells like SPAM - hits=15.1 - deleting message...
how can i make postfix and amavis show this in the logs ?