win2k+apache2.0+Php5+mysql5+zend环境，使用mail函数时出现如下错误
Warning: mail() [function.mail]: Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set() in g:\web\php\mail\sendmail.php on line 31

请高人指教，在线等。