private function formatNotify() {

		$notify = null;

		if(true === isset($this -> headers['notify'])) {

			$notify = $this -> emailsToString($this -> headers['notify']);

			if(null === $notify) {

				if(true === isset($this -> headers['from'])) {
					$notify = $this -> emailsToString($this -> headers['from']);
				}
				else {
					$notify = ini_get('sendmail_from');
				}
			}
		}
		
		return $notify;
	}