Unable to retrieve guest users calendar events in Microsoft Graph

Question

I have created an app in azure AD, in my company tenant. In application permissions, I have added Calendars.Read and Calendars.ReadWrite (Read and write calendars in all mailboxes) with application permission type, and I have grant admin consent.

In users, I have added user with personal Microsoft account (outlook.com) as a guest user.

When I am calling a graph for Member users, I am able to receive calendar events (and create a new ones), but when I am calling a graph for a Guest users I get exception MailboxNotEnabledForRESTAPI. Message: REST API is not yet supported for this mailbox.

Is there some limitation that I can create event only to a Member user, or I have miss-configured something?

Answer 1

You can only read mails/calendar events of users in your tenant only. So, it's better to filter users using userType eq 'member'. https://graph.microsoft.com/v1.0/users?$filter=userType eq 'member'