Sending email by EWS using Oauth2.0

Question

Hi there,

I have question 'bout using EWS with Oauth2.0 Client Credential.

In our directory, there're users with member type and guest type, however, all of our administrators are from Microsoft directory(using v-xxx@microsoft.com) and they are under guest.

My question is if it's possible to use credential client grant type, and use EWS to send email behalf of these guest users?

Thank you.

Answer 1

Yes, as long as the app has been granted impersonation permissions. OAuth is supported for the client credential flow, but without impersonation you will not be able to do this.