Microsoft to shut down EWS in Exchange Online by April 2027

Microsoft will permanently retire Exchange Web Services (EWS) in Exchange Online by April 2027, accelerating the shift away from legacy email integration tools towards its newer Microsoft Graph platform.

The Exchange Team said in a blog post on Thursday that EWS will be disabled through a phased, tenant-by-tenant process beginning in October 2026, before a complete shutdown in 2027. The change applies only to Microsoft 365 and Exchange Online, with no impact on on-premises Exchange Server deployments.

EWS, built nearly two decades ago, has long been used by enterprises and third-party vendors to connect applications with Exchange mailboxes. Microsoft said the service no longer meets modern requirements around security, scale and reliability.

The company noted that Microsoft Graph has now reached near-complete feature parity for most EWS use cases, and that many applications — including Microsoft’s own products — have already migrated away from the older framework.

Under the new plan, Microsoft will introduce additional administrative controls. A feature arriving in early 2026 will allow organisations to create an AppID allow list, restricting EWS access only to approved applications.

From October 1, 2026, tenants that have not explicitly configured their settings will see EWS disabled by default. Microsoft said any tenant still using the default configuration will automatically have EWS blocked, potentially interrupting workflows that rely on older integrations.

Administrators who still require EWS temporarily will have limited options, including re-enabling access through Exchange Online PowerShell and maintaining an allow list during the transition period.

The final shutdown will begin on April 1, 2027, when EWS will be fully disabled and tenant-level controls removed. Microsoft stressed that no extensions will be granted beyond that date.

The move reflects a broader industry push to reduce reliance on legacy interfaces and consolidate enterprise software ecosystems around more modern, cloud-first APIs. For organisations still dependent on EWS-based applications, the next year will be critical for auditing usage and completing migrations to Microsoft Graph.