Microsoft is retiring Exchange Web Services (EWS). This process will begin in October 2026 and end with the complete shutdown of EWS in 2027. I recently mentioned this in the German blog post Exchange Online: Zeitplan für das Ende von EWS veröffentlicht (use the translate feature of my German blog). Microsoft has now published a post on how administrators of Exchange Online tenants can identify apps that use EWS and solve the issue.
EWS shutdown October 1, 2026 – April 1, 2027
According to its announcement, Microsoft plans to start blocking EWS in Exchange Online by October 1, 2026, at the latest. However, Microsoft will already block EWS access for users without EWS license rights (e.g., certain kiosk and frontline worker license types) from the end of June 2026. This may result in EWS-based integrations for such users no longer working. Further details may be read at this blog post (use the translate feature of my German blog).
