public function queue($to, array $params = [], $priority = 0, $files = [], $bcc = null)
    {
        $text = nl2br($this->renderAttribute('text', $params));
        $subject = $this->renderAttribute('subject', $params);
        EmailManager::getInstance()->queue(
            $this->from,
            $to,
            $subject,
            $text,
            $priority,
            $files,
            $bcc
        );
        return true;
    }