diff --git a/UI/WebServerResources/js/Common/utils.js b/UI/WebServerResources/js/Common/utils.js
index d339b6396..306466cef 100644
--- a/UI/WebServerResources/js/Common/utils.js
+++ b/UI/WebServerResources/js/Common/utils.js
@@ -353,3 +353,11 @@ function contrast(hex) {
     return 'white';
   }
 }
+
+function guid() {
+  function S4() {
+    return (((1+Math.random())*0x10000)|0).toString(16).substring(1); 
+  }
+  
+  return (S4() + S4() + "-" + S4() + "-4" + S4().substr(0,3) + "-" + S4() + "-" + S4() + S4() + S4()).toLowerCase();
+}
diff --git a/UI/WebServerResources/js/Preferences/Preferences.service.js b/UI/WebServerResources/js/Preferences/Preferences.service.js
index db1bbb577..6e3baaa52 100644
--- a/UI/WebServerResources/js/Preferences/Preferences.service.js
+++ b/UI/WebServerResources/js/Preferences/Preferences.service.js
@@ -166,8 +166,13 @@
 
     // We swap _$key -> $key to avoid an Angular bug (https://github.com/angular/angular.js/issues/6266)
     labels = _.object(_.map(preferences.defaults.SOGoMailLabelsColors, function(value, key) {
-      if (key.charAt(0) == '_' && key.charAt(1) == '$')
+      if (key.charAt(0) == '_' && key.charAt(1) == '$') {
+        // New key, let's take the value and flatten it
+        if (key.length > 2 && key.charAt(2) == '$') {
+          return [value[0].toLowerCase().replace(/[ \(\)\/\{%\*<>\\\"]/g, "_"), value];
+        }
         return [key.substring(1), value];
+      }
       return [key, value];
     }));
 
diff --git a/UI/WebServerResources/js/Preferences/PreferencesController.js b/UI/WebServerResources/js/Preferences/PreferencesController.js
index 19bee7644..9e3dd667f 100644
--- a/UI/WebServerResources/js/Preferences/PreferencesController.js
+++ b/UI/WebServerResources/js/Preferences/PreferencesController.js
@@ -148,7 +148,9 @@
     }
     
     function addMailLabel() {
-      vm.preferences.defaults.SOGoMailLabelsColors.new_label =  ["New label", "#aaa"];
+      // See $omit() in the Preferences services for real key generation
+      var key = '_$$' + guid();
+      vm.preferences.defaults.SOGoMailLabelsColors[key] =  ["New label", "#aaa"];
     }
 
     function removeMailLabel(key) {