PHP, Classes, and PEAR

WinXP Pro SP1 PHP 4.3.9 I am still learning PHP so please be gentle with me! LOL I am trying to send mail from my PC. For some reason it is not working. The line is mail($email_to, $email_subject, $email_message); There is no error or failure but the email is never sent. I also found a Mail class that extends Mail as a PEAR (extends) class. I tried that but could not get it to work either. It keep saying that it could not find the class. Fatal error: Cannot instantiate non-existent class: mail_mail I did the PEAR_ENV.reg so it is in the registry. So my questions is how do I get PHP to find the PEAR classes? And how do I get mail to work? Help, as always, is greatly appreciated. Mike