电子邮件不发送到一个特定域

We are using amazon server and I am using PHP, Codeigniter framework.

Below is the script which I am using for sending emails. It is working when I send an email to Gmail domain email id (abc@gmail.com) but it is not working on some specific domain name email id (abc@xyzdmainname.com).

  public function sendMail() {
  $to = 'abc@xyzdomain.com';
  $fromEmail = 'pqr@gmail.com';
  $fromName = 'pqr';
  $subject = 'Testing';
  $message = 'Testing of email';
  $newFile = ''
  $this->CI->load->library('email');
  $this->CI->email->mailtype = 'html';
  $this->CI->email->from($fromEmail, $fromName);
  $this->CI->email->to($to);
  $this->CI->email->subject($subject);
  $this->CI->email->message($message);
  if (!empty($newFile)) {
  $this->CI->email->attach($newFile);
  }
  $result = $this->CI->email->send();
  $message = '';
  if ($result) {
  return 1;
  } else {
  echo $this->CI->email->print_debugger();
  return 0;
  };

Please let me help what-what case may be here for fail sending email on a particular domain.

and How I can overcome this issue.