I am trying to work with public folders on Exchange Online using EWS, and I need to do a POX Autodiscover request to determine the X-PublicFolderInformation header value as described here:
https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-route-public-folder-hierarchy-requests#bk_makeautodrequest
I am getting this error:
I am using OAuth and Exchange Online, but I try doing the same request to an on premise Exchange server using NTLM, it works fine. Is this something that is not supported with OAuth, or could there be some other configuration changes I need to make in order for this to work? Thanks!