Just to follow up on this after testing changing the code to this worked:
$header = "POST /cgi-bin/webscr HTTP/1.1\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n";
$header .= "Host: www.paypal.com\r\n";
$header .= "Connection: close\r\n\r\n";
$fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30);
for some reason no version of the code using the ipnpb.paypal.com domain would work
Regards,
Dave Buchholz
I-CRE8 Limited