Mine
public text v1 · immutable iptables -A OUTPUT -o $EXTERNAL_INTERFACE -p TCP \
--sport $UNPRIVPORTS --dport 465 -s $EXTERNAL_IP -d $SMTP_SRVR -j ACCEPT
iptables -A INPUT -i $EXTERNAL_INTERFACE -p TCP -m state --state ESTABLISHED,RELATED \
--sport 465 --dport $UNPRIVPORTS -s $SMTP_SRVR -d $EXTERNAL_IP -j ACCEPT