MSGraph API 400 Authentication Error with /users/{id}/messages

Question

Hello,

I'm attempting to read the emails of a user who's part of my Azure Active Directory as part of an automation test. I have to preface I'm not using the MSAL library as I want the implementation to be as lightweight as possible.

I've authenticated and gotten a token fine by using ClientCredentials (tenant id, client id and secret) and by using jwt.ms, I've verified that the token has the correct permissions "roles": [ "User.Read.All", "Mail.Read" ]and hasn't expired.

The issue I'm having is I can get a list of the users by doing a get("https://graph.microsoft.com/v1.0/users", headers=self._headers()" However as soon as I try to get the e-mails with get(f"https://graph.microsoft.com/v1.0/users/{user_id}/messages", headers=mail_headers) It will always return a 400 AuthenticationError, Error authenticating with resource.

This is def _headers(self): return {"Authorization": f"Bearer {self.azure_client.token"}", "Host":"graph.microsoft.com"}which just returns the token in a dictionary for the requests rather than typing it out constantly and mail_headers just appends "Prefer":"outlook.body-text"to the headers as per the documentation.

Any advice or things I should check would be greatly appreciated.

Thanks in advance,

Brennan

Answer 1

Hi DP,

Thanks for reaching out. For Graph SDK related queries please post them on the respective Graph Github SDK forum or the Graph Feedback Forum. Can you reproduce the issue using Graph Explorer or Postman applications?

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Thanks.