Microsoft Exchange Online

And you have double-checked that the credentials you are using are in fact valid and should have access? The error suggests it's a credential issue.

If the credentials are OK, check the Windows logs on the server to see if there's any additional information. One common issue when connecting to Exchange Online is that Microsoft nowadays only allows TLS 1.2 connections but that should produce a different kind of an error message as far as I know. This support article has further information: Azure AD TLS 1.0 and 1.1 Error

And you have double-checked that the credentials you are using are in fact valid and should have access? The error suggests it's a credential issue.

If the credentials are OK, check the Windows logs on the server to see if there's any additional information. One common issue when connecting to Exchange Online is that Microsoft nowadays only allows TLS 1.2 connections but that should produce a different kind of an error message as far as I know. This support article has further information: Azure AD TLS 1.0 and 1.1 Error

At the beginning, we had the TLS error after that we followed the steps described in the documents and turned on TLS1.2. At last, we get this error.

We double checked all the credentials. Tenant ID, Client ID, Client Secret, Folder everything perfect. Any other credentials have to check?

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It looks like you don't have the right permissions on this app registration.
Can you show a screenshot of the API Permissiong on that app registration?

Hi there

is there any solution so far, i ran into the same issue. TLS 1.2 is set and the credentials are the correct one...