My paypal IPN script suddenly does not works anymore. in paypal IPN history the IPN's are failing now and the HTTP response code stays empty. what could be causing this and how to fix it? I have not changed any code, it just stopped working.
here is my php code:
<?php
   //Change these with your information
$paypalmode = ''; //Sandbox for testing or empty ''
$dbusername     = 'xxx'; //db username
$dbpassword     = 'xxx'; //db password
$dbhost     = 'xxx.com'; //db host
$dbname     = 'xxx'; //db name
if($_POST)
{
    if($paypalmode=='sandbox')
    {
        $paypalmode     =   '.sandbox';
    }
    $req = 'cmd=' . urlencode('_notify-validate');
    foreach ($_POST as $key => $value) {
        $value = urlencode(stripslashes($value));
        $req .= "&$key=$value";
    }
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://www'.$paypalmode.'.paypal.com/cgi-bin/webscr');
    curl_setopt($ch, CURLOPT_HEADER, 0);
    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_HTTPHEADER, array('Host: www'.$paypalmode.'.sandbox.paypal.com'));
    $res = curl_exec($ch);
    curl_close($ch);
    if (strcmp ($res, "VERIFIED") == 0)
    {
        $transaction_id = $_POST['txn_id'];
        $ebaytxnid = $_POST['ebay_txn_id1'];
        $payerid = $_POST['payer_id'];
        $firstname = $_POST['first_name'];
        $lastname = $_POST['last_name'];
        $ebayname = $_POST['auction_buyer_id'];
        $email = $_POST['payer_email'];
        $shippingname = $_POST['address_name'];
        $shippingstreet = $_POST['address_street'];
        $shippingcity = $_POST['address_city'];
        $shippingstate = $_POST['address_state'];
        $shippingzip = $_POST['address_zip'];
        $shippingcountry = $_POST['address_country'];
        $shippingcountrycode = $_POST['address_country_code'];
        $currency = $_POST['mc_currency'];
        $paymentfee = $_POST['payment_fee'];
        $total = $_POST['payment_gross'];
        $mcfee = $_POST['mc_fee'];
        $mcgross = $_POST['mc_gross'];
        $ebayitemno = $_POST['item_number'];
        $ebayitemname = $_POST['item_name'];
        $quantity = $_POST['quantity1'];
        $paymentdate = $_POST['payment_date'];
        $mdate= date('Y-m-d h:i:s',strtotime($paymentdate));
        $paymentstatus = $_POST['payment_status'];
        $payerstatus = $_POST['payer_status'];
        $paymenttype = $_POST['payment_type'];
        $addressstatus = $_POST['address_status'];
        $forauction = $_POST['for_auction'];
        $protectioneligibility = $_POST['protection_eligibility'];
        $otherstuff = json_encode($_POST);
        $conn = mysql_connect($dbhost,$dbusername,$dbpassword);
        if (!$conn)
        {
         die('Could not connect: ' . mysql_error());
        }
        mysql_select_db($dbname, $conn);
        // insert in our IPN record table
        $query = "INSERT INTO ibn_table
        (itransaction_id,iebaytxnid,ipayerid,ifirstname,ilastname,iebayname,iemail,ishippingname,ishippingstreet,ishippingcity,ishippingstate,ishippingzip,ishippingcountry,ishippingcountrycode,icurrency,ipaymentfee,itotal,imcfee,imcgross,iebayitemno,iebayitemname,iquantity,itransaction_date,ipaymentstatus,ipayerstatus,ipaymenttype,iaddressstatus,iforauction,iprotectioneligibility,ieverything_else)
        VALUES
        ('$transaction_id','$ebaytxnid','$payerid','$firstname','$lastname','$ebayname','$email','$shippingname','$shippingstreet','$shippingcity','$shippingstate','$shippingzip','$shippingcountry','$shippingcountrycode','$currency','$paymentfee','$total','$mcfee','$mcgross','$ebayitemno','$ebayitemname','$quantity','$mdate','$paymentstatus','$payerstatus','$paymenttype','$addressstatus','$forauction','$protectioneligibility','$otherstuff')";
        if(!mysql_query($query))
        {
            //mysql error..!
        }
        mysql_close($conn);
    }
}
?>
 
     
    