diff --git a/data/web/inc/functions.mailbox.inc.php b/data/web/inc/functions.mailbox.inc.php
index 6ecb3a94..70dd0e1f 100644
--- a/data/web/inc/functions.mailbox.inc.php
+++ b/data/web/inc/functions.mailbox.inc.php
@@ -757,6 +757,14 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
           $password2    = $_data['password2'];
           $name         = ltrim(rtrim($_data['name'], '>'), '<');
           $quota_m			= intval($_data['quota']);
+          if ((!isset($_SESSION['acl']['unlimited_quota']) || $_SESSION['acl']['quarantine_notification'] != "1") && $quota_m === 0) {
+            $_SESSION['return'][] = array(
+              'type' => 'danger',
+              'log' => array(__FUNCTION__, $_action, $_type, $_data_log, $_attr),
+              'msg' => 'unlimited_quota_acl'
+            );
+            return false;
+          }
           if (empty($name)) {
             $name = $local_part;
           }
@@ -2000,6 +2008,15 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
               );
               continue;
             }
+            // if already 0 == ok
+            if ((!isset($_SESSION['acl']['unlimited_quota']) || $_SESSION['acl']['unlimited_quota'] != "1") && ($quota_m == 0 && $is_now['quota'] != 0)) {
+              $_SESSION['return'][] = array(
+                'type' => 'danger',
+                'log' => array(__FUNCTION__, $_action, $_type, $_data_log, $_attr),
+                'msg' => 'unlimited_quota_acl'
+              );
+              return false;
+            }
             $stmt = $pdo->prepare("SELECT `quota`, `maxquota`
               FROM `domain`
                 WHERE `domain` = :domain");
diff --git a/data/web/inc/init_db.inc.php b/data/web/inc/init_db.inc.php
index a66d2ab3..3c553bfd 100644
--- a/data/web/inc/init_db.inc.php
+++ b/data/web/inc/init_db.inc.php
@@ -3,7 +3,7 @@ function init_db_schema() {
   try {
     global $pdo;
 
-    $db_version = "27012019_1217";
+    $db_version = "30032019_1905";
 
     $stmt = $pdo->query("SHOW TABLES LIKE 'versions'");
     $num_results = count($stmt->fetchAll(PDO::FETCH_ASSOC));
@@ -464,6 +464,7 @@ function init_db_schema() {
           "filters" => "TINYINT(1) NOT NULL DEFAULT '1'",
           "ratelimit" => "TINYINT(1) NOT NULL DEFAULT '1'",
           "spam_policy" => "TINYINT(1) NOT NULL DEFAULT '1'",
+          "unlimited_quota" => "TINYINT(1) NOT NULL DEFAULT '0'",
           "alias_domains" => "TINYINT(1) NOT NULL DEFAULT '0'",
           ),
         "keys" => array(
diff --git a/data/web/lang/lang.de.php b/data/web/lang/lang.de.php
index b5fc4642..4d0352d0 100644
--- a/data/web/lang/lang.de.php
+++ b/data/web/lang/lang.de.php
@@ -19,6 +19,7 @@ $lang['footer']['cancel'] = 'Abbrechen';
 $lang['footer']['hibp_nok'] = 'Übereinstimmung gefunden! Dieses Passwort ist potentiell gefährlich!';
 $lang['footer']['hibp_ok'] = 'Keine Übereinstimmung gefunden.';
 
+$lang['danger']['unlimited_quota_acl'] = "Unendliche Quota untersagt durch ACL";
 $lang['danger']['mysql_error'] = "MySQL Fehler: %s";
 $lang['danger']['redis_error'] = "Redis Fehler: %s";
 $lang['danger']['unknown_tfa_method'] = "Unbekannte TFA Methode";
@@ -405,6 +406,7 @@ $lang['acl']['bcc_maps'] = 'BCC Maps';
 $lang['acl']['filters'] = 'Filter';
 $lang['acl']['ratelimit'] = 'Rate limit';
 $lang['acl']['recipient_maps'] = 'Empfängerumschreibungen';
+$lang['acl']['unlimited_quota'] = 'Unendliche Quota für Mailboxen';
 $lang['acl']['prohibited'] = 'Untersagt durch Richtlinie';
 
 $lang['mailbox']['quarantine_notification'] = 'Quarantäne-Benachrichtigung';
diff --git a/data/web/lang/lang.en.php b/data/web/lang/lang.en.php
index 0329a92d..3efe810e 100644
--- a/data/web/lang/lang.en.php
+++ b/data/web/lang/lang.en.php
@@ -20,6 +20,7 @@ $lang['footer']['cancel'] = 'Cancel';
 $lang['footer']['hibp_nok'] = 'Matched! This is a potentially dangerous password!';
 $lang['footer']['hibp_ok'] = 'No match found.';
 
+$lang['danger']['unlimited_quota_acl'] = "Unlimited quota prohibited by ACL";
 $lang['danger']['mysql_error'] = "MySQL error: %s";
 $lang['danger']['redis_error'] = "Redis error: %s";
 $lang['danger']['unknown_tfa_method'] = "Unknown TFA method";
@@ -418,6 +419,7 @@ $lang['acl']['bcc_maps'] = 'BCC maps';
 $lang['acl']['filters'] = 'Filters';
 $lang['acl']['ratelimit'] = 'Rate limit';
 $lang['acl']['recipient_maps'] = 'Recipient maps';
+$lang['acl']['unlimited_quota'] = 'Unlimited quota for mailboxes';
 $lang['acl']['prohibited'] = 'Prohibited by ACL';
 
 $lang['mailbox']['quarantine_notification'] = 'Quarantine notifications';