oauth 2.0 - Sending Email using Azure EWS with OAuth2.0 Client Credential

Question

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?

For now, I tried to use EASendMail sdk to achieve this task. However, whenever I use account within our directory(member type) I get "There is no SMTP email associated" which is what I expected, 'cause we do not have email address associated with these users. But when I tried using (v-xxx@microsoft.com) , "Mailbox does not exist" error is raised.

Thank you.

question from:https://stackoverflow.com/questions/65912412/sending-email-using-azure-ews-with-oauth2-0-client-credential

Answer 1

You can do as long as the app has been granted impersonation permissions. OAuth is supported for the client credential flow(app permissions) & impersonation to do so.