SharePoint Calendar - Outlook creating cached events

Question

I have a SharePoint calendar with restricted edit permissions. Only a few people have edit but everyone else has read permissions. This works in SharePoint.

However when the calendar is connected to outlook, we have found that readonly users can create an event in their local outlook view for that calendar. So instead of getting permission denied, they seem to be able to create local cached events on the calendar.

The SharePoint calendar does not display these items but their local outlook client will display them until they delete and reconnect the calendar (at which point it is accurate again, only showing the events that exist in SharePoint).

I'm sure disabling outlook cache would help here but I'd rather not do that if I don't have to.

Any other thoughts on how to prevent this?

Answer 1

Have you tried to add permission to calender in Outlook?

Right Click the calendar > click Properties > Click Permissions > Add

Reference: Calendar Permissions in Outlook

Answer 2

I'm almost positive this is a flaw in the sharepoint calendar design. When connecting a sharepoint calendar to outlook, it seems outlook sort of sets up a local cache calendar. This calendar lacks any permissions that the online calendar has and as a result it seems to let the local user make changes but it can never push them to sharepoint because the online calendar actually adheres to the permissions settings.

I'd wager this is an oversight by microsoft or due to some technical limitation but because it's such an edge case, I've given up expecting microsoft to fix it.