public function _sendMail()
    {
        // If sending multiple messages per session use existing adapter
        if (!($this->_connection instanceof Zend_Mail_Protocol_Smtp)) {
            // Check if authentication is required and determine required class
            $connectionClass = 'Zend_Mail_Protocol_Smtp';
            if ($this->_auth) {
                $connectionClass .= '_Auth_' . ucwords($this->_auth);
            }
            if (!class_exists($connectionClass)) {
                // require_once 'Zend/Loader.php';
                Zend_Loader::loadClass($connectionClass);
            }
            $this->setConnection(new $connectionClass($this->_host, $this->_port, $this->_config));
            $this->_connection->connect();
            $this->_connection->helo($this->_name);
        } else {
            // Reset connection to ensure reliable transaction
            $this->_connection->rset();
        }

        // Set sender email address
        $this->_connection->mail($this->_mail->getReturnPath());

        // Set recipient forward paths
        foreach ($this->_mail->getRecipients() as $recipient) {
            $this->_connection->rcpt($recipient);
        }

        // Issue DATA command to client
        $this->_connection->data($this->header . Zend_Mime::LINEEND . $this->body);
    }