I spent some time playing around with Azure AD OAuth 2.0.
An access token obtained with scope https://outlook.office.com/mail.read throws 401 Unauthorized when used with Microsoft Graph.
Similarly, an access token obtained with scope https://graph.microsoft.com/mail.read throws 401 Unauthorized when used with Outlook REST API endpoints.
Also, I get an error if I mention both the scopes while authorizing a user.
Is it possible to have access tokens that allow access to both Microsoft Graph and Outlook REST API endpoints?
I am building an emailing app. Initially, I will build basic features like syncing/sending emails.
I will be using Microsoft Graph, since it supports all that I need presently and Microsoft recommends it over individual service API endpoints.
I am worried about future. The OAuth access tokens that I will obtain at present will have scope https://graph.microsoft.com/mail.read. In future, it may happen that a new feature I want to build is not supported by Microsoft Graph but it is supported By Outlook REST API endpoints. At such time I would want to use the Outlook REST API endpoints.
Do I have to maintain two sets of OAuth access token for every user? Also asking every user to re-auth is not a good idea.