add_hook('message_outgoing_headers', array($this, 'message_headers')); } function message_headers($args) { $this->load_config(); // additional email headers $additional_headers = rcmail::get_instance()->config->get('additional_message_headers',array()); foreach($additional_headers as $header=>$value){ if (null === $value) { unset($args['headers'][$header]); } else { $args['headers'][$header] = $value; } } return $args; } } ?>