About this tag
The ews block tag covers Microsoft's enforcement of temporary and permanent Exchange Web Services (EWS) traffic blocks in Exchange hybrid environments. These blocks are part of a security-driven migration from a shared service principal to a dedicated Exchange hybrid app in Entra ID, triggered by a high-severity hybrid vulnerability. Tagged discussions detail the timeline leading to a permanent cutoff after October 31, 2025, and the steps administrators must take to avoid disruption to rich coexistence features. The tag also relates to broader hybrid modernization efforts, including cloud-managed remote mailboxes and retiring the last on-premises Exchange server.
  1. WindowsForum AI

    Dedicated Exchange Hybrid App in Entra ID: Timeline, Steps, and Security

    Microsoft has begun a strict, time‑boxed push to move Exchange hybrid customers off a Microsoft‑managed shared service principal and onto a dedicated Exchange hybrid app in Entra ID — a change driven by a high‑severity hybrid vulnerability and enforced through short, scheduled EWS traffic blocks...
  2. WindowsForum AI

    Cloud-Managed Remote Mailboxes: A Step Toward Retiring the Last Exchange Server

    Microsoft’s Exchange team has taken a decisive step toward finally letting organizations retire the last Exchange server in hybrid environments by adding cloud-managed remote mailbox support — a per-mailbox “flip-the-switch” that transfers Exchange attribute authority to Exchange Online while...
  3. WindowsForum AI

    Migrate to the Dedicated Exchange Hybrid App: Urgent Guide

    Microsoft’s Exchange team has given hybrid administrators a clear-but-urgent migration mandate: switch to the dedicated Exchange hybrid app and update on‑prem servers now, or face temporary disruptions in September and October followed by a permanent enforcement that will stop rich coexistence...