Prevent crash

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

@@ -1224,12 +1224,14 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
         @TargetApi(Build.VERSION_CODES.O)
         private void onNotifyContactDelete(TupleMessageEx message) {
+            if (message.from != null && message.from.length > 0) {
                 NotificationManager nm = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
 
                 InternetAddress from = (InternetAddress) message.from[0];
                 String channelName = "notification." + from.getAddress().toLowerCase();
                 nm.deleteNotificationChannel(channelName);
             }
+        }
 
         private void onAddContact(TupleMessageEx message) {
             for (Address address : message.from) {