MC1227454 Exchange Web Services retirement: EWS begins being disabled October 1, 2026 · fully retired April 1, 2027, including allow lists

Microsoft is always retiring something.
Know what breaks next in your tenant.

The EWS usage report in the Microsoft 365 admin center tells you which Application IDs still call EWS — as raw GUIDs, with no names attached. This tool resolves them: which application each GUID is, which vendors have shipped a Microsoft Graph fix, and which items actually need your attention in the next days.

Decode your EWS usage report → MSP fleet view
Runs entirely in your browser. Your report never leaves your machine — no upload, no account, no tracking.
f8d98a96-0999-43f5-8af3-69971c7bb423 Apple Internet Accounts Action required
3153c72b-35a8-465b-84d8-dfb56651836a CodeTwo Sent Items Update Vendor fix available
d3590ed6-52b3-4102-aeff-aad2292ab01c Microsoft Office / Outlook classic No action needed

From GUID soup to a to-do list in three steps

01

Export the report Microsoft already gives you

M365 admin center → Reports → Usage → Exchange → EWS usage → Export. You get App IDs, SOAP actions, call volume, last activity.

02

Paste it into the decoder

The full CSV, a fragment, or a bare list of Application IDs from sign-in logs — all accepted. Matching happens locally against our App ID database.

03

Get names, vendors, and fix status

Example: “This GUID is Cisco Unity Connection voicemail sync — affected after October unless upgraded to 15 SU4 (Field Notice FN74365).” Every entry cites its public source.

Managing 20 tenants? This deadline applies to every one of them.

The admin-center EWS report is single-tenant, portal-only, and aggregated weekly. We’re building the managed-services view: every client tenant’s EWS exposure on one remediation dashboard, weekly change tracking, and digest cards delivered into Microsoft Teams.

Try the free fleet view (paste-based) →

The retirement rail

Every few years Microsoft retires a load-bearing protocol, and every tenant relearns the same lesson. Here’s where we are:

OCT 2022

Basic Auth retired

Exchange Online kills basic authentication. Scripts and scanners everywhere break.

MAY 2026

O365 Connectors off

Teams webhook connectors stop functioning after the May 18–22 shutoff.

OCT 1, 2026 ◉ next up

EWS disablement begins

EWS starts being switched off per tenant. Allow lists buy time — nothing more.

APR 1, 2027

EWS fully retired

Allow lists stop working. No extensions, no exceptions, per Microsoft.

Why this exists

Deprecations are never one and done. Basic authentication in 2022. Office 365 Connectors in 2026. Now Exchange Web Services. Each retirement strands working software and hands administrators the same project: determine what we run that is about to stop working. What Breaks Next tracks Microsoft’s retirement calendar so you don’t have to — starting with the largest one currently scheduled.

Key references: Microsoft Learn — Deprecation of EWS in Exchange Online · Exchange Team blog · EWSAllowedAppIDs announcement.