Exchange Connector Error

[Aytch]

Good morning,

I am trying to set up a Microsoft Exchange Online connection to PowerBI to get some reporting on a mailbox. It doesn't matter what mailbox I try, even my own, I keep getting a Expression.Error: Access to the resource is forbidden.

I have signed in and out many times, tried many mailboxes, some shared, some user, but I have full access to each of them. It doesn't seem to matter what I try, I keep getting that same error message.

Does anyone have any experience using this connector that can shed some light on the issue?

Thank you!

[Zanqueta · Accepted solution]

Hi , @Aytch

The “Expression.Error: Access to the resource is forbidden” error occurs because the Exchange Online connector in Power BI still depends on Basic Authentication, which is disabled on most Microsoft 365 tenants. Even with full mailbox access, authentication fails.

Microsoft recommends replacing the Exchange connector with Microsoft Graph API through Power Query, which uses modern authentication and provides reliable access to mailbox data. Continuing with the Exchange connector would require Basic Authentication to be re-enabled for Exchange Web Services, which is not recommended and may cease to work.

[Aytch]

Thank you, that makes sense!