php 发送emial配置问题~!

引用:

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 D:\AppServ\www\mail\email.php on line 284
请教高手出现上面的错误
是smtp没装,还是php配置要改哪些设置.