HELP with mail()

I created the following email program from a email function that I know works in another program. When I create a simple form page listed below and submit it. It echos the $email and the $username and it writes it to the page. So it is finding the variables within the transfering url in the form of a post. It doesn't give me an error message but I don't get an email? Should the Linux server not be executing the mail() function? What the beep!??????? Again thanks in advance for any help. Zhimmy <?php $email = strtolower($email); echo "$email, $username"; function sendEmail($email, $username) { $mailTo = "$username <$email>"; $mailSubject = "Your registration confirmation..."; $mailBody = "Dear $name,\n\nYour details have been added to my email list.\n\n To unsubscribe click on the link below\nhttp://www.sitename.com/mail.php?action=unsubscribe&email=$email"; mail($email, "Registration Confirmation", $mailBody, "From: \r\n" ."Reply-To: \r\n" ."X-Mailer: PHP/" . phpversion()); } ?> Form: <form action='mail1.php' method='POST'> Username: <br> <input type='text' name='username' class='register_box'> <br> Email: <br> <input type='text' name='email' class='register_box'> <br> Password: <br> <input type='password' name='password' class='register_box'> <br> <input type='submit' name='register' value='New Registration!' class='register_box'> </form> --------------------------------- All new Yahoo! Mail --------------------------------- Get news delivered. Enjoy RSS feeds right on your Mail page.