for i in $(awk -F: '{print $1}' /etc/userdomains); do
  echo $i \
    $(dig @8.8.8.8 NS +short $i | sed 's/\.$//g' | tail -n2 | sort) \
    $(dig @8.8.8.8 +short $i | grep -v [a-zA-Z] | tail -n1);

done | grep [A-Za-z] | sort -n +3 -2 | column -t