Zend_Mail_Transport_SMTP抛出致命错误

I am using following code to send email using godaddy SMTP.

$config = array('auth' => 'login', 'username' => 'user@mydowmain.com', 'password' =>     'mypass');
  $transport = new Zend_Mail_Transport_Smtp('smtpout.secureserver.net', $config);
  $mail = new Zend_Mail('UTF-8');
  $mail->setBodyText('This is the text of the mail again.');
  $mail->setFrom('user@mydowmain.com', 'User');
  $mail->addTo('me@domain.com', 'Me');
  $mail->setSubject('This is mail test again');
  $mail->send($transport);

Email works. I can see the email in inbox. But on the page it throws a fatal error

Fatal error: Exception thrown without a stack frame in Unknown on line 0

I am unable to trace it out. Any help in this regard will be highly appreciated. Thanks