what is smtp,smtp_port?and how can it get?
If you have a Windows server, you need to specify the address (domain name och IP) to an sending e-mail server. On real operating systems PHP will always use your local Mail Transer Agent (MTA).
This is clearly explained in the PHP manual: http://php.net/manual/en/mail.configuration.php#ini.smtp
Also, this question is better asked on Serverfault.com