PHP Code:
function hotmailExists($email)
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://accountservices.passport.net/pp1300/memberexists.srf");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_COOKIE, "MSPMemberExists=$email");
$response = curl_exec($ch);
curl_close($ch);
return stripos($response, "MSPMemberExists=MemberExists") !== false;
}