CCalendar::IsExchangeEnabled

static function IsExchangeEnabled($userId = false)
{
	if (isset(self::$arExchEnabledCache[$userId]))
	{
		return self::$arExchEnabledCache[$userId];
	}

	if (!IsModuleInstalled('dav') || COption::GetOptionString("dav", "agent_calendar") !== "Y")
	{
		$res = false;
	}
	elseif (!Loader::includeModule('dav'))
	{
		$res = false;
	}
	elseif ($userId === false)
	{
		$res = CDavExchangeCalendar::IsExchangeEnabled();
	}
	else
	{
		$res = CDavExchangeCalendar::IsExchangeEnabled() && CDavExchangeCalendar::IsExchangeEnabledForUser($userId);
	}

	self::$arExchEnabledCache[$userId] = $res;

	return $res;
}