Singapore – Microsoft has set out a phased plan to withdraw Exchange Web Services (EWS) from Microsoft 365 and Exchange Online, with default disablement beginning in October 2026 and permanent shutdown scheduled for 1 April 2027.
The change applies only to cloud environments in Microsoft 365 and Exchange Online. EWS in on-premises Exchange Server deployments will continue to operate.
The Microsoft Exchange Team mentioned in a post how the decision reflects the age of the technology and evolving requirements around security, scalability and reliability. Microsoft Graph now provides near-equivalent functionality for most EWS scenarios, and many Microsoft and third-party applications have already transitioned. The move is intended to reduce reliance on legacy interfaces and simplify the platform.
From 1 October 2026, EWS will be turned off by default for customers who have not taken administrative action. Control will be managed through the EWSEnabled setting, alongside a new AppID Allow List feature due in early 2026, enabling organisations to permit access only for specified applications. Customers who configure an Allow List and set EWSEnabled to True by the end of August 2026 will not be automatically blocked in October.
Microsoft plans to pre-populate Allow Lists in September 2026 for tenants that have not created one, based on observed usage. Administrators can temporarily re-enable EWS if required, although service interruption may occur.
Organisations are advised to review EWS usage and begin migrating applications to Microsoft Graph. From April 2027, EWS will be permanently disabled in Exchange Online, with no extensions beyond that date. Microsoft will provide monthly updates and may conduct brief test disruptions to help customers identify dependencies ahead of the final withdrawal.
