#!/bin/bash

declare clients=( hiljainen.susurrando.com www.susurrando.com oc.koti.site)

rm /etc/postfix/allowed_clients
touch /etc/postfix/allowed_clients
chown postfix.postfix /etc/postfix/allowed_clients
chmod o-rwx /etc/postfix/allowed_clients

for client in "${clients[@]}"
do
    client_ip=$(dig "${client}" | grep -v '^;' |grep "\sA\s" | awk '{print($5)}')
    echo "${client_ip}" >> /etc/postfix/allowed_clients
done