Send Mail using Socket

<?php
//
// This function was originally a part of phpBB2 (http://www.phpbb.com).
//
function smtp_mail($to, $subject, $message, $headers = '')
{
    $recipients = explode(',', $to);
    $user = '<your mail id>';
    $pass = '<your password>';
    // The server details that worked for you in the above step
    $smtp_host = '<server>';
    //The port that worked for you in the above step
    $smtp_port = 465;

    if (!($socket = fsockopen($smtp_host, $smtp_port, $errno, $errstr, 15)))
    {
      echo "Error connecting to '$smtp_host' ($errno) ($errstr)";
    }

    server_parse($socket, '220');

    fwrite($socket, 'EHLO '.$smtp_host."\r\n");
    server_parse($socket, '250');

    fwrite($socket, 'AUTH LOGIN'."\r\n");
    server_parse($socket, '334');

    fwrite($socket, base64_encode($user)."\r\n");
    server_parse($socket, '334');

    fwrite($socket, base64_encode($pass)."\r\n");
    server_parse($socket, '235');

    fwrite($socket, 'MAIL FROM: <'.$user.'>'."\r\n");
    server_parse($socket, '250');

    foreach ($recipients as $email)
    {
        fwrite($socket, 'RCPT TO: <'.$email.'>'."\r\n");
        server_parse($socket, '250');
    }

    fwrite($socket, 'DATA'."\r\n");
    server_parse($socket, '354');

    fwrite($socket, 'Subject: '
      .$subject."\r\n".'To: <'.implode('>, <', $recipients).'>'
      ."\r\n".$headers."\r\n\r\n".$message."\r\n");

    fwrite($socket, '.'."\r\n");
    server_parse($socket, '250');

    fwrite($socket, 'QUIT'."\r\n");
    fclose($socket);

    return true;
}

//Functin to Processes Server Response Codes
function server_parse($socket, $expected_response)
{
    $server_response = '';
    while (substr($server_response, 3, 1) != ' ')
    {
        if (!($server_response = fgets($socket, 256)))
        {
          echo 'Error while fetching server response codes.', __FILE__, __LINE__;
        }
    }

    if (!(substr($server_response, 0, 3) == $expected_response))
    {
      echo 'Unable to send e-mail."'.$server_response.'"', __FILE__, __LINE__;
    }
}
?>