Outlook slow when using shared calendars

Applies to: Microsoft Outlook 2013, 2016, 2019

Symptoms

When you open a shared calendar, Outlook takes a long time to display the results.

Solution

Turn off public folder caching as follows:

1. In Outlook choose File > Account Settings > Account Settings
2. In the Account Settings dialog select your main email account and click Change...
3. In the Change Account dialog click More Settings...
4. In the Microsoft Exchange dialog, select the Advanced tab
5. Under Cached Exchange Mode Settings, uncheck Download shared folders and click OK to confirm
6. Click Next then Finish then Close to confirm the change