public function action(string $message, string $link, string $class = 'btn btn-primary') : Mail
  {
    $this->body .= "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" class=\"{$class}\">
<tbody>
  <tr>
    <td align=\"left\">
      <table border=\"0\" cellpadding=\"0\" cellspacing=\"0\">
        <tbody>
          <tr>
            <td>
              <a href=\"{$link}\" target=\"_blank\">{$message}</a>
            </td>
          </tr>
        </tbody>
      </table>
    </td>
  </tr>
</tbody>
</table>
";
    return $this;
  }