Basic Auth and Exchange Online – February 2020 Update

Greg Taylor - EXCHANGE For our product we rely on EWS, OAB and Autodiscover. Since our product is deployed on desktop and targets end users we are doing our best to make the experience as smooth as possible. That means we rely on the authentication to all these services being unified, preferably through OAuth. Authenticating to one service using OAuth and to another through a Basic authentication goes against the philosophy. I am glad to hear that 3rd-party OAuth support for OAB is coming but at the moment it's a blocker for us to make the transition. We have been communicating this to Microsoft through multiple channel for almost a year now. It feels like a blow to us to send customers to the vendors to complain to us.

Note that at present there's no alternative API for us to use. We have to keep supporting EWS and OAB for legacy on-premise installation. We're willing to transition to different APIs when connecting to Exchange Online accounts but at the moment there's no replacement with the same functionality. The APIs return different subsets of the results and many of them require permissions needing administrator consent. That gives Outlook and Outlook for Mac unfair advantage because they are pre-approved to get the correct permissions.