Forwarding hosts in postscreen

data/conf/postfix/main.cf

@@ -24,7 +24,7 @@ milter_default_action = accept
 milter_protocol = 6
 minimal_backoff_time = 300s
 plaintext_reject_code = 550
-postscreen_access_list = permit_mynetworks, cidr:/opt/postfix/conf/postscreen_access.cidr
+postscreen_access_list = permit_mynetworks, cidr:/opt/postfix/conf/postscreen_access.cidr, tcp:127.0.0.1:10027
 postscreen_bare_newline_enable = no
 postscreen_blacklist_action = drop
 postscreen_cache_cleanup_interval = 24h

data/conf/postfix/master.cf

@@ -55,3 +55,5 @@ zeyple    unix  -       n       n       -       -       pipe
   -o smtpd_recipient_restrictions=permit_mynetworks,reject
   -o mynetworks=127.0.0.0/8
   -o smtpd_authorized_xforward_hosts=127.0.0.0/8
+
+127.0.0.1:10027 inet  n       n       n       -       0      spawn user=nobody argv=/opt/postfix/conf/whitelist_forwardinghosts.sh

data/conf/postfix/whitelist_forwardinghosts.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+while true; do
+	read QUERY
+	QUERY=($QUERY)
+	if [ "${QUERY[0]}" != "get" ]; then
+		echo "500 dunno"
+		continue
+	fi
+	echo $(curl -s http://172.22.1.251:8081/forwardinghosts.php?host=${QUERY[1]})
+done