Mail function not mailing

[gobbles]

Could somebody please tell me why this code isnt mailing me ... It goes through the whole script .. even displays the thank you message ... But i never recieve the email.

<?php

$sender_email = "Users Email Address: \t$sender_email\n";

$recipient = "[e-mail]";
$subject = "I wanna recieve the NSI newsletter";

mail( $recipient, $subject, $sender_email);

include ("header.htm");
echo "Thank you for registering\n";
include("footer.htm");

?>

[coditoergosum]

Need more info. What OS are you using? Do you have a working mail server running on your server? If you don't, you can specify a different smtp server to use in your php.ini file. If you do have a mail server running on your server, then you'll need to do some more debugging. The mail() function returns true if the mail was successfully passed on to your mail server, false otherwise. You should check that first of all, and then go from there... if it returns false, it's a PHP problem (or no mail server), if it returns true then it's a mail server problem.