Exchange Web Services (EWS) in Exchange Online will be phased out starting October 1, 2026, with full retirement by April 1, 2027, replaced by Microsoft Graph. Organizations must migrate workflows, configure AppID AllowList to continue EWS use after October 2026, or face permanent EWS access removal.
Applies to: Exchange Online
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).