code: public function transport($to, $subject, $message, $additional_headers = '', $additional_parameters = '')
      {
          return mail($to, $subject, $message, $additional_headers, $additional_parameters);
      }
docs: Messages sender : prepare the whole content and send the e-mail
  
  @param   string $to
  @param   string $subject
  @param   string $message
  @param   string $additional_headers
  @param   string $additional_parameters
  @return  mixed
  @see     mail()