No, the manual states "Drop the connection immediately with a 521 SMTP reply" and that's not happening.
The 521 drop comes *after* the pregreet and DNSBL checks. Mar 3 09:59:54 localhost postfix/dnsblog[84376]: addr 85.54.217.239 listed by domain zen.spamhaus.org as 127.0.0.11 Mar 3 09:59:54 localhost postfix/dnsblog[84376]: addr 85.54.217.239 listed by domain zen.spamhaus.org as 127.0.0.4 Mar 3 10:00:00 localhost postfix/postscreen[84375]: PASS pregreet test [85.54.217.239]:5089 Mar 3 10:00:00 localhost postfix/postscreen[84375]: DNSBL rank 2 for [85.54.217.239]:5089 Mar 3 10:00:00 localhost postfix/postscreen[84375]: FAIL [85.54.217.239]:5089 Mar 3 10:00:00 localhost postfix/postscreen[84375]: DROP Mar 3 10:00:00 localhost postfix/postscreen[84375]: > [85.54.217.239]:5089: 521 5.7.1 Service unavailable -- Sent from: http://postfix.1071664.n5.nabble.com/Postfix-Users-f2.html
