I am trying to develop an application using PubSubHubbub in PHP I have successfully subscribed to a RSS using this link but But I don't receive any notification when the source is up can anyone help me with this
the callback script on my server is as follows
<?php
if (isset($_GET['hub_challenge'])) {
$xml = $_GET['hub_challenge'];
}
else {
$xml=file_get_contents("php://input");
}
$to = "XXXXX";
$subject = "HTML email";
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";
mail($to,$subject,$xml,$headers);XXXXX
?>