diff --git a/UI/MailerUI/UIxMailActions.m b/UI/MailerUI/UIxMailActions.m
index 3da8b7540..6d1439176 100644
--- a/UI/MailerUI/UIxMailActions.m
+++ b/UI/MailerUI/UIxMailActions.m
@@ -156,12 +156,13 @@
 
   co = [self clientObject];
   us = [[context activeUser] userSettings];
-  moduleSettings = [us objectForKey: @"Mail"];
+  if (!(moduleSettings = [us objectForKey: @"Mail"]))
+    [us setObject:[NSMutableDictionary dictionnary] forKey: @"Mail"];
   msguid = [co nameInContainer];
   currentMailbox = [[co container] nameInContainer];
   currentAccount = [[[co container] container] nameInContainer];
   keyForMsgUIDs = [NSString stringWithFormat:@"/%@/%@", currentAccount, currentMailbox];
-
+  
   if (isCollapsing)
     {
       // Check if the module threadsCollapsed is created in the userSettings
@@ -196,14 +197,12 @@
           if ((mailboxThreadsCollapsed = [threadsCollapsed objectForKey:keyForMsgUIDs]))
             {
               [mailboxThreadsCollapsed removeObject:msguid];
-      
               if ([mailboxThreadsCollapsed count] == 0)
                 [threadsCollapsed removeObjectForKey:keyForMsgUIDs];
             }
         }
-      // TODO : Manage errors
+    // TODO : Manage errors
     }
-  
   [us synchronize];
 }
 
diff --git a/UI/WebServerResources/MailerUI.js b/UI/WebServerResources/MailerUI.js
index 64f864a3d..b30926591 100644
--- a/UI/WebServerResources/MailerUI.js
+++ b/UI/WebServerResources/MailerUI.js
@@ -35,7 +35,7 @@ var messageCheckTimer;
 
 // Variables for feature threadsCollapsing
 var displayThreadElement = false;
-var cachedThreadsCollapsed = UserSettings.Mail.threadsCollapsed;
+var cachedThreadsCollapsed = (UserSettings.Mail ? UserSettings.Mail.threadsCollapsed: []);
 
 /* We need to override this method since it is adapted to GCS-based folder
  references, which we do not use here */
@@ -2608,8 +2608,10 @@ function onMenuToggleMessageFlag(event) {
 
 function refreshUserSettingsCallback(http) {
     var allUserSettings = http.response.evalJSON();
-    UserSettings.Mail = allUserSettings.Mail;
-    cachedThreadsCollapsed = UserSettings.Mail.threadsCollapsed;
+    if (UserSettings.Mail) {
+        UserSettings.Mail = allUserSettings.Mail;
+        cachedThreadsCollapsed = UserSettings.Mail.threadsCollapsed;
+    }
     refreshMailbox();
 }