protected function _getTransport()
    {
        if ($this->_mailer === 'smtp') {
            $transport = Swift_SmtpTransport::newInstance($this->_site_settings->smtphost, $this->_site_settings->smtpport)
            ->setUsername($this->_site_settings->smtpuser)
            ->setPassword($this->_site_settings->smtppass);
        } elseif ($this->_mailer === 'sendmail') {
            $transport = Swift_SendmailTransport::newInstance('/usr/sbin/exim -bs');
        } else {
            $transport = Swift_MailTransport::newInstance();
        }

        return $transport;
    }