Small behavior improvement

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

@@ -5683,9 +5683,10 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                             message.accountProtocol != EntityAccount.TYPE_IMAP);
 
             int i = (message.importance == null ? EntityMessage.PRIORITIY_NORMAL : message.importance);
-            popupMenu.getMenu().findItem(R.id.menu_set_importance_low).setEnabled(!EntityMessage.PRIORITIY_LOW.equals(i));
-            popupMenu.getMenu().findItem(R.id.menu_set_importance_normal).setEnabled(!EntityMessage.PRIORITIY_NORMAL.equals(i));
-            popupMenu.getMenu().findItem(R.id.menu_set_importance_high).setEnabled(!EntityMessage.PRIORITIY_HIGH.equals(i));
+            boolean can = (message.uid != null || message.accountProtocol == EntityAccount.TYPE_POP);
+            popupMenu.getMenu().findItem(R.id.menu_set_importance_low).setEnabled(can && !EntityMessage.PRIORITIY_LOW.equals(i));
+            popupMenu.getMenu().findItem(R.id.menu_set_importance_normal).setEnabled(can && !EntityMessage.PRIORITIY_NORMAL.equals(i));
+            popupMenu.getMenu().findItem(R.id.menu_set_importance_high).setEnabled(can && !EntityMessage.PRIORITIY_HIGH.equals(i));
 
             popupMenu.getMenu().findItem(R.id.menu_move_to)
                     .setEnabled(message.uid != null && !message.folderReadOnly)