The PHP mail function (1 reply)

I have got the following error message when I attempted to send an email using the PHP mail function:

Warning: 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 C:\wamp\www\phppower\proj5\fileincludes\myprocessform.php on line 51
Can someone please help with how I should go about altering the relevant settings in my PHP ini to be able to send emails using the PHP mail function.
Thanks