Core_Email::_smtp_authenticate

protected function _smtp_authenticate()
{
    if ( ! $this->_smtp_auth)
    {
        return true;
    }

    if ($this->smtp_user === '' && $this->smtp_pass === '')
    {
        $this->_set_error_message('lang:email_no_smtp_unpw');
        return false;
    }

    $this->_send_data('AUTH LOGIN');

    $reply = $this->_get_smtp_data();

    if (strpos($reply, '334') !== 0)
    {
        $this->_set_error_message('lang:email_failed_smtp_login', $reply);
        return false;
    }

    $this->_send_data(base64_encode($this->smtp_user));

    $reply = $this->_get_smtp_data();

    if (strpos($reply, '334') !== 0)
    {
        $this->_set_error_message('lang:email_smtp_auth_un', $reply);
        return false;
    }

    $this->_send_data(base64_encode($this->smtp_pass));

    $reply = $this->_get_smtp_data();

    if (strpos($reply, '235') !== 0)
    {
        $this->_set_error_message('lang:email_smtp_auth_pw', $reply);
        return false;
    }

    return true;
}