docker-mailserver/target/bin/delmailuser

#! /bin/bash

DATABASE=${DATABASE:-/tmp/docker-mailserver/postfix-accounts.cf}
ALIAS_DATABASE="/tmp/docker-mailserver/postfix-virtual.cf"

usage() {
	echo "Usage: delmailuser <-y> <user@domain> <user2@anotherdomain> ..."
	echo "	-y: don't prompt for confirmations"
}

errex() {
	echo -e "$@" 1>&2
	exit 1
}

escape() {
	echo "${1//./\\.}"
}

while getopts ":y" OPT; do
  case $OPT in
    y)
      MAILDEL="y"
      ;;
   \?)
		 usage; errex "Invalid option: -$OPTARG"
     ;;
  esac
done

shift $((OPTIND-1))

[ -z "$@" ] && { usage; errex "No user specifed"; }
[ -s "$DATABASE" ] || exit 0

# Protect config file with lock to avoid race conditions
(
  flock -e 200

  for USER in "$@"; do
    # very simple plausibility check
    [[ "$USER" != *"@"*"."* ]] && errex "No valid address: $USER"
    MAILARR=(${USER//@/ })
    # XXX $USER must not contain /s and other syntactic characters
    USER=$(escape "$USER")
    sed -i "/^"$USER"|/d" $DATABASE
    [ $? != 0 ] && errex "$USER couldn't be deleted in $DATABASE. $?"
    # Delete all aliases where the user is the only recipient( " $USER$" )
    # Delete user only for all aliases that deliver to multiple recipients ( ",$USER" "$USER," )
    sed -i -e "/ "$USER"$/d" \
        -e "s/,"$USER"//g" \
        -e "s/"$USER",//g" $ALIAS_DATABASE
    [ $? = 0 ] && echo "$USER and potential aliases deleted." || errex "Aliases for $USER couldn't be deleted in $ALIAS_DATABASE. $?"
    if [ "$MAILDEL" != "y" ]; then
      read -p "Do you want to delete the mailbox as well(all mails will be removed)?(y/n) " MAILDEL
      echo
    fi
    [ "$MAILDEL" != "y" ] && errex "Leaving the mailbox untouched. If you want to delete it at a later point use \"sudo docker exec mail rm -R /var/mail/${MAILARR[1]}/${MAILARR[0]}\""
    rm -r -f /var/mail/${MAILARR[1]}/${MAILARR[0]}
    [ $? = 0 ] && echo "Mailbox deleted." || errex "Mailbox couldn't be deleted: $?"
  done

) 200<$DATABASE