private void listView_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            // navigate to the list view item
            DependencyObject dep = (DependencyObject)e.OriginalSource;

            while ((dep != null) && !(dep is ListViewItem))
            {
                dep = VisualTreeHelper.GetParent(dep);
            }

            if (dep == null)
            {
                return;
            }

            ListViewItem item         = (ListViewItem)dep;
            EmailModel   myDataObject = (EmailModel)item.Content;

            Dispatcher.BeginInvoke(new Action(() => {
                var emailContentWindow = new EmailContent(myDataObject);
                emailContentWindow.Show();
            }));
        }