As a part of Microsoft's Secure Future Initiative (SFI), security remains our top priority. In alignment with SFI, Exchange Server is implementing several changes to enhance the security of Exchange ...
Updated Aug 11, 2025
Version 11.0
Blog Post
We have a multi-tenant hybrid organization. We managed to configure the dedicated hybrid app (and auth server on-premises) for each tenant. Now we have the problem, that the free/busy lookup only works for one tenant.
Test-Oauth, using a hybrid on-premises user that is synced to the working tenant, Shows success.
Test-Oauth, using a hybrid on-premises user that is synced to a non working tenant, Shows error. In the error text we can see that it is using the wrong (working) tenant.
Information:[OAuthTokenBuilder:GetAzureADAppToken] trying to get the apptoken from the auth server 'EvoSts - xxx' for resource 'https://outlook.office365.com', tenantId 'yyy', userDomain 'zzz'
-> userDomain zzz does not belong to tenant yyy / evosts xxx but to another one!