Sending Elastic Email emails using PHP

mail.php

<?php

define('ELASTIC_MAIL_API_KEY', '');

/**
 * Sends an email using Elastic Mail.
 * @param {String} $to Receiver's email address.
 * @param {String} $subject Email submit.
 * @param {String} $body_text Text body.
 * @param {String} $body_html HTML body.
 * @param {String} $from Sender's email address.
 * @param {String} $fromName Name of sender.
 * @return {Boolean}
 */
function sendElasticEmail($to, $subject, $body_text, $body_html, $from, $fromName) {
  $res = "";

  $data = "username=".urlencode("[email protected]");
  $data .= "&api_key=".urlencode(ELASTIC_MAIL_API_KEY);
  $data .= "&from=".urlencode($from);
  $data .= "&from_name=".urlencode($fromName);
  $data .= "&to=".urlencode($to);
  $data .= "&subject=".urlencode($subject);
  if($body_html)
    $data .= "&body_html=".urlencode($body_html);
  if($body_text)
    $data .= "&body_text=".urlencode($body_text);

  $header = "POST /mailer/send HTTP/1.0\r\n";
  $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
  $header .= "Content-Length: " . strlen($data) . "\r\n\r\n";
  $fp = fsockopen('ssl://api.elasticemail.com', 443, $errno, $errstr, 30);

  if(!$fp)
    return false;
  else {
    fputs ($fp, $header.$data);
    while (!feof($fp)) {
      $res .= fread ($fp, 1024);
    }
    fclose($fp);
  }
  return true;
}

?>