Folders can always contain folders

app/src/main/java/eu/faircode/email/AdapterFolder.java

@@ -382,13 +382,14 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                 return false;
 
             final TupleFolderEx folder = items.get(pos);
-            if (!folder.selectable || folder.tbd != null)
+            if (folder.tbd != null)
                 return false;
 
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
 
             PopupMenuLifecycle popupMenu = new PopupMenuLifecycle(context, powner, view);
 
+            if (folder.selectable) {
                 popupMenu.getMenu().add(Menu.NONE, 0, 0, folder.getDisplayName(context)).setEnabled(false);
                 popupMenu.getMenu().add(Menu.NONE, R.string.title_synchronize_now, 1, R.string.title_synchronize_now);
 
@@ -441,9 +442,11 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                             popupMenu.getMenu().add(Menu.NONE, R.string.title_delete_channel, 15, R.string.title_delete_channel);
                         }
                     }
-
-                popupMenu.getMenu().add(Menu.NONE, R.string.title_create_sub_folder, 15, R.string.title_create_sub_folder);
                 }
+            }
+
+            if (folder.account != null && !folder.accountPop)
+                popupMenu.getMenu().add(Menu.NONE, R.string.title_create_sub_folder, 16, R.string.title_create_sub_folder);
 
             popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                 @Override