diff --git a/lib/filesystem/FileManager.php b/lib/filesystem/FileManager.php
index 55cd769bc7f0e8b72fa25e91d1da42d025df97b0..13527a9004b6cd07b83f4e6698bd4e57fb9dc2e9 100644
--- a/lib/filesystem/FileManager.php
+++ b/lib/filesystem/FileManager.php
@@ -1667,7 +1667,7 @@ class FileManager
      */
     public static function getInboxFolder(User $user)
     {
-        $top_folder = Folder::findTopFolder($user->id, 'user');
+        $top_folder = Folder::findTopFolder($user->id);
         if (!$top_folder) {
             return null;
         }
@@ -1710,7 +1710,7 @@ class FileManager
      */
     public static function getOutboxFolder(User $user)
     {
-        $top_folder = Folder::findTopFolder($user->id, 'user');
+        $top_folder = Folder::findTopFolder($user->id);
         if (!$top_folder) {
             return null;
         }
diff --git a/lib/models/Folder.php b/lib/models/Folder.php
index 7b666219eb0115932ca8b26eb7c0c8e4d1b080be..b73571c133f9c20fd842c151c058d0804a4b3f38 100644
--- a/lib/models/Folder.php
+++ b/lib/models/Folder.php
@@ -370,14 +370,15 @@ class Folder extends SimpleORMap implements FeedbackRange
      * Note that the range_id parameter is mandatory!
      *
      * @param string range_id The ID of the Stud.IP object whose top folder shall be found.
+     * @param string folder_type The expected folder type related to the Stud.IP object (defaults to RootFolder, use MessageFolder for the top folder of a message)
      *
      * @returns Folder|null Folder object on success or null, if no folder can be created.
      **/
-    public static function findTopFolder($range_id)
+    public static function findTopFolder($range_id, $folder_type = 'RootFolder')
     {
         $top_folder = self::findOneBySQL(
-            "range_id = ? AND parent_id=''",
-            [$range_id]
+            "range_id = ? AND folder_type = ? AND parent_id=''",
+            [$range_id, $folder_type]
         );
 
         //top_folder may not exist!
@@ -390,7 +391,7 @@ class Folder extends SimpleORMap implements FeedbackRange
                 return null;
             }
 
-            $top_folder = self::createTopFolder($range_id, $range_type);
+            $top_folder = self::createTopFolder($range_id, $range_type, $folder_type);
         }
 
         return $top_folder;