docker-mailserver/target/bin/restrict-access

#! /bin/bash

# shellcheck source=../bin-helper.sh
. /usr/local/bin/bin-helper.sh

MODE="${1}"
USER="${3}"

function usage  {	echo "Usage: ${0} <add|del|list> <send|receive> [<email@domain.com>]" ; }

[[ -z ${MODE} ]] && errex "missing parameters: <add|del|list> <send|receive> [<email@domain.com>]"

case ${2} in
  send)
    DATABASE="/tmp/docker-mailserver/postfix-send-access.cf"
    ;;
  receive)
    DATABASE="/tmp/docker-mailserver/postfix-receive-access.cf"
    ;;
  *)
    usage
    errex "missing parameters. Specify \"send\" or \"receive\""
    ;;
esac

if [[ -z ${USER} ]] && [[ ${MODE} != list ]]
then
  read -r -p "User(user@domain.com): " USER
  echo
  [[ -z ${USER} ]] && errex "User must not be empty"
fi

case ${MODE} in
  add)
    grep -qi "^$(escape "${USER}")" "${DATABASE}" 2>/dev/null && errex "User \"${USER}\" already denied to ${2} mails"

    if [[ ! -f ${DATABASE} ]]
    then
      # shellcheck disable=SC2015
      [[ ${DATABASE} = *"send"* ]] && \
          sed -i 's|smtpd_sender_restrictions =|smtpd_sender_restrictions = check_sender_access texthash:/tmp/docker-mailserver/postfix-send-access.cf,|' /etc/postfix/main.cf \
        || sed -i 's|smtpd_recipient_restrictions =|smtpd_recipient_restrictions = check_recipient_access texthash:/tmp/docker-mailserver/postfix-receive-access.cf,|' /etc/postfix/main.cf

      service postfix reload >/dev/null
    fi

    echo -e "${USER} \t\t REJECT" >>"${DATABASE}"
  ;;

  del)
    sed -ie "/^$(escape "${USER}")/d" "${DATABASE}" 2>/dev/null || errex "User \"${USER}\" not found."
  ;;

  list)
    grep "REJECT" "${DATABASE}" 2>/dev/null || echo "Everyone is allowed to ${2} mails."
    ;;
  *)
    usage
    errex "missing mode. Specify \"add\", \"del\" or \"list\""
  ;;

esac