public function massageMessageBody(array $message) {

    // @see: SwiftMailer::massageMessageBody()
    $line_endings = Settings::get('mail_line_endings', PHP_EOL);
    $message['body'] = Markup::create(implode($line_endings, array_map(function ($body) {
      // If the field contains no html tags we can assume newlines will need be
      // converted to <br>.
      if (strlen(strip_tags($body)) === strlen($body)) {
        $body = str_replace("\r", '', $body);
        $body = str_replace("\n", '<br>', $body);
      }
      return check_markup($body, 'full_html');
    }, $message['body'])));
    return $message;
  }