function f_postfix {
  echo "[$SCRIPT_COUNT] Postfix"

  postconf -e disable_vrfy_command=yes
  postconf -e smtpd_banner="\$myhostname ESMTP"
  postconf -e smtpd_client_restrictions=permit_mynetworks,reject
  postconf -e inet_interfaces=loopback-only

  systemctl restart postfix.service

  if [[ $VERBOSE == "Y" ]]; then
    systemctl status postfix.service --no-pager
    echo
  fi

  ((SCRIPT_COUNT++))
}