public function markUnread($user, array $params) {
		if (is_null($user) || ! is_string($user) || (! strpos($user, '@') === false)) {
			throw new InvalidArgumentException('user must be string representing userId');
		}
		$params = $this->_filterParams($params, array('label','folder','message_id','raw'), array('label','folder','message_id'));
		if ($params === false) {
			throw new InvalidArgumentException("params array contains invalid parameters or misses required parameters");
		}
		$email_account = $params['label'];
		$folder = $params['folder'];
		$messageId = $params['message_id'];
		return $this->delete($user, "email_accounts/" . rawurlencode($email_account) . "/folders/" . rawurlencode($folder) . "/messages/" . rawurlencode($messageId) . "/read");
	}