[reject rcpt]
log 1 pass = May  8 08:26:55 mail postfix/postscreen[22055]: NOQUEUE: reject: RCPT from [157.122.148.242]:47407: 550 5.7.1 Service unavailable; client [157.122.148.242] blocked using bl.spamcop.net; from=<kos@mafia.network>, to=<z13699753428@vip.163.com>, proto=ESMTP, helo=<XL-20160217QQJV>

rule = 3306
alert = 6
decoder = postfix-reject

[domain not found]
log 1 pass = Jun 18 20:59:29 mybox postfix/postscreen[12181]: NOQUEUE: reject: RCPT from [213.158.187.41]:45263: 450 4.3.2 Service currently unavailable; from=<purchase@otherfolks.com>, to=<media@example.com>, proto=ESMTP, helo=<some.box.net>

rule = 3303
alert = 5
decoder = postfix-reject