About the error message that UserPrincipalName is invalid

Question

I want to refer to the calendar of someone other than myself with the Microsoft graph API.
However, if you specify the following and execute with delegated access, the error message "xxx@X .com is invalid" is returned.
In addition, "xxx@X .com" is the UserPrincipalName of a sharer other than yourself. Outlook is shared using the free version. Accounts are Microsoft accounts.
What is the cause of the error message?
By the way, if you specify your own UserPrincipalName, it will work.

https://graph.microsoft.com/v1.0/users/xxx[@](/users/na/?userId=83e82d08-687d-492d-a122-29c7f3076b43).com/calendar
(Use Calendars.ReadWrite.Shared)

Answer 1

Hi @ooumi77 ,

To share the calendar you can follow the below steps in outlook:

In calendar Home page click on settings and select view all outlook settings

From settings select calendar ->Shared calendars ->select a calendar

Choose the user you want to share the calendar and add the permission "can edit" or "delegate"

If you have shared the calendar like the above mentioned step then please check the UPN by running the endpoint /users.

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