PHP Mail 帮忙！！！

我写了这一段：
<?php
$to = "abc@yahoo.com";
$subject = "Test mail";
$message = "Hello! This is a simple email message.";
$from = "xyz@yahoo.com";
$headers = "From: $from";
echo "$to\n <br/>";
echo "$subject\n<br/>";
echo "$message\n<br/>";
echo "$from\n<br/>";
echo "$headers\n<br/>";
if(mail($to,$subject,$message,$headers))
echo "Mail Sent.";
else
echo "Mail not sent";
?>

我一直都拿到Mail not sent。

是不是我的setting有问题？请帮个忙，谢谢。

engswee

<?php
$to      = 'nobody@example.com';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: webmaster@example.com' . "\r\n" .
    'Reply-To: webmaster@example.com' . "\r\n" .
    'X-Mailer: PHP/' . phpversion();

mail($to, $subject, $message, $headers);
?>