我无法向Outlook发送电子邮件

Hi everyone i have already tried email sending using php code igniter. but it send to only gmail and yahoo mail. it doesn't send to any other server like live.com , Outlook etc. please help me.

$this->load->helper('email');
$this->load->library('email'); // load the library
$config = Array(
                         'protocol' => 'smtp',
                         'smtp_host' => 'mail.xxxxxx.com',
                         'smtp_port' => 25,
                         'smtp_user' => 'info@xxxxxx.com', // change it to yours
                         'smtp_pass' => '', // change it to yours
                         'mailtype' => 'html',
                         'charset' => 'utf-8',
                         'wordwrap' => TRUE,
                         'crlf' => '
',
                        'newline' => '
'
                        );  
$this->load->library('email', $config);