Microsoft was not releasing feature updates for Exchange Web Services in Exchange Online and now says it will block EWS requests from non-Microsoft apps to Exchange Online starting Oct. 1, 2026.

For those unfamiliar with Exchange Web Services (EWS), it's a cross-platform API designed to allow apps to "access mailbox items such as email messages, meetings, and contacts from Exchange Online ...

Microsoft's cross-platform Exchange Web Services (EWS) API will end on October 1, 2026. This change will affect Exchange Online customers utilizing EWS to access emails and contacts.