IPN paypal it not working - paypal

Question

I have a problem. In January the code for PayPal IPN was working, and in February is stopped working. What could it change?
Here is the code
<?php
$raw_post_data = file_get_contents('php://input');
$raw_post_array = explode('&', $raw_post_data);
$myPost = array();
foreach ($raw_post_array as $keyval) {
$keyval = explode ('=', $keyval);
if (count($keyval) == 2)
$myPost[$keyval[0]] = urldecode($keyval[1]);
}
$req = 'cmd=_notify-validate';
if(function_exists('get_magic_quotes_gpc')) {
$get_magic_quotes_exists = true;
}
foreach ($myPost as $key => $value) {
if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) {
$value = urlencode(stripslashes($value));
} else {
$value = urlencode($value);
}
$req .= "&$key=$value";
}
$ch = curl_init('https://www.paypal.com/cgi-bin/webscr');
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Connection: Close'));
if( !($res = curl_exec($ch)) ) {
curl_close($ch);
exit;
}
curl_close($ch);
if (strcmp ($res, "VERIFIED") == 0) {
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
if ($_POST['mc_gross'] != NULL)
$payment_amount = $_POST['mc_gross'];
else
$payment_amount = $_POST['mc_gross1'];
$payment_currency = $_POST['mc_currency'];
$txn_id = $_POST['txn_id'];
$receiver_email = $_POST['receiver_email'];
$payer_email = $_POST['payer_email'];
$custom = $_POST['custom'];
$adres = "jankowski095#gmail.com";
$tytul = "Zakupiono przedmiot";
$wiadomosc = "Zakupiono ";
mail($adres, $tytul, $wiadomosc);
} else if (strcmp ($res, "INVALID") == 0) {
$adres = "jankowski095#gmail.com";
$tytul = "Tytuł wiadomoścasdi no";
$wiadomosc = "IPN nie działa.";
mail($adres, $tytul, $wiadomosc);
}
?>
I do not know why it stopped working from PayPal I did not get any notification of changes in the software. Help me please