Graph API Calendar Query in Hybrid Environment

Question

We have a hybrid Exchange setup with Exchange 2016 CU 22 and I'm trying to query all calendars of all colleagues through Graph to create a report on who has a certain appointment in their calendar.

I've gone through the necessary setup to let Graph query the on-premise Exchange server and it works for almost everyone (about 300 users) except for a frustrating few (about 15).

I connect to Graph through an app registration with the API application permissions

Calendars.Read
Calendars.ReadWrite These have been admin granted

The query I'm trying:

https://graph.microsoft.com/v1.0/users/[userprincipalname]/calendarview?startdatetime=2021-11-19T00:00:00.000Z&enddatetime=2021-12-03T00:00:00.000Z

but also the following as a test:

https://graph.microsoft.com/v1.0/users/[userprincipalname]/calendar

Both throw this error:

{
  "error": {
    "code": "ResourceNotFound",
    "message": "Resource could not be discovered.",
    "innerError": {
      "date": "2021-12-02T16:22:29",
      "request-id": "840548e2-5362-457f-9259-81546bd56950",
      "client-request-id": "840548e2-5362-457f-9259-81546bd56950"
    }
  }
}

This happens with unlicensed users as wel as users with a license that implies permissions for an Exchange Online mailbox.
These that don't work, all have an on-premise mailbox but there are loads of others with on-premise mailbox that I can query just fine.
I can query those 'failed' mailboxes through the on-premise Exchange server API but I'd rather not do that for the production version of this script (not scaleable)

Graph API Calendar Query in Hybrid Environment

0 Answers0