Question

I’m using PHPMailer and it uses fsockopen to access the SMTP server.

But the machine has two IPs with different reverse DNS records. So in email headers I got the following:

Received: from one-server.tld (HELO another-server.tld) ...

I need to hide one-server.tld in favor of another-server.tld. But I need both IPs with their current RDNS settings.

Answer 1

I think its not possible using fsockopen. But its possible in curl, fopen and stream functions. What you need is stream_socket_client() function.

Here are some ways to achieve it.

1. Using context parameters which can be used in fopen function family and stream function family. See the example.

   $opts = array(
       'socket' => array(
           'bindto' => '192.168.0.100:0',
       ),
   );
   // create the context...
   $context = stream_context_create($opts);
   $contents = fopen('http://www.example.com', 'r', false, $context);
   

   Also stream_socket_client

   $fp = stream_socket_client("tcp://www.example.com:80", $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $opts);
   if (!$fp) {
       echo "$errstr ($errno)<br />\n";
   } else {
       fwrite($fp, "GET / HTTP/1.0\r\nHost: www.example.com\r\nAccept: */*\r\n\r\n");
       while (!feof($fp)) {
           echo fgets($fp, 1024);
       }
       fclose($fp);
   }
   

2. Using socket_bind. PHP.NET got a simple example here.