MC1227454 Exchange Web Services (EWS) retirement update
[Introduction] We're updating the timeline and process for the retirement of Exchange Web Services (EWS) in Exchange Online. As previously announced, EWS will be retired in favor of Microsoft Graph, which offers improved security, modern authentication, and broader capability support. A phased disablement begins October 1, 2026, with permanent shutdown starting April 1, 2027. [When this will happen:] Phased EWS disablement begins: October 1, 2026 Full and permanent EWS retirement: April 1, 2027 EWS App AllowList feature availability: Coming soon (before retirement milestones) [How this affects your organization:] Who is affected: Organizations using custom or vendor applications that rely on EWS Workflows involving mail, calendar, or integrations that use EWS This change only impacts Exchange Online; Exchange Server (on-premises) is not affectedWhat will happen: Beginning October 1, 2026