Microsoft has started disabling Exchange Web Services (EWS) by default in Exchange Online. This change impacts Apple's Mail and Calendar apps on Mac, which currently use EWS to sync Microsoft 365 work accounts. Microsoft had previously announced its intention to disable EWS, ceasing new feature development in 2018 and planning the shutdown for 2023. Organizations that have explicitly kept EWS enabled are not immediately affected. The rollout is phased, meaning some Mac users might lose access sooner than others. IT administrators have the option to re-enable EWS temporarily. However, EWS will be permanently shut down in Exchange Online on April 1, 2027. Apple is aware of the situation and is collaborating with Microsoft. They plan to transition Mac apps to the Microsoft Graph API in an upcoming macOS update. This update has not yet been released, and current beta notes do not mention Graph support. Affected organizations can either maintain EWS or switch Mac users to a compatible client like Microsoft Outlook. This shutdown exclusively affects Microsoft's cloud-hosted servers, not on-premises Exchange servers or iOS/iPadOS devices, which use Exchange ActiveSync.