If your team uses Apple Mail on a Mac to read company email, a quiet change Microsoft is making right now could break it. Microsoft has started disabling Exchange Web Services (EWS) in Exchange Online — the older protocol Apple Mail relies on to sync with Microsoft 365 — and the shutdown becomes permanent on 1 April 2027. There are no extensions planned. For businesses with Macs in the office, this is worth understanding now, while there is still time to act calmly.
What EWS is, and why it's going away
Exchange Web Services is a long-standing API that mail and calendar apps have used for nearly two decades to talk to Exchange servers. Microsoft has been steering everything towards its modern replacement, Microsoft Graph, which supports modern authentication and stronger security. EWS is being retired from Exchange Online in phases: a gradual disablement began on 1 October 2026, rolling out tenant by tenant, and the final shutdown — when EWS stops working in Exchange Online entirely — is set for 1 April 2027. This affects Microsoft 365 and Exchange Online only; on-premises Exchange servers are not affected.
Why Mac users are most affected
Here's the part that matters to everyday users: the built-in Mail and Calendar apps on macOS connect to Microsoft 365 work accounts over EWS. When EWS is blocked in your tenant, Apple Mail on a Mac can stop syncing work email and calendars — no new messages, no calendar updates.
The good news for mobile users: iPhones and iPads are not affected. They sync through a different protocol (ActiveSync), so staff who work from an iPhone will carry on as normal. And users on the Outlook app — on Mac, Windows or mobile — are on Microsoft's supported path and should be fine, provided the app is reasonably up to date.
The timeline in plain terms
- From 1 October 2026: Microsoft began blocking EWS by default, tenant by tenant. Admins who still need it must explicitly allow-list the applications that use it — unlisted apps lose access.
- Until 1 April 2027: with the allow-list configured, EWS applications such as Apple Mail can keep working. This is a stopgap, not a solution.
- 1 April 2027: EWS is permanently disabled in Exchange Online. No setting keeps it alive after this date. Apple Mail on Mac will need a different way to sync — or a different app.
Apple is reportedly working on moving macOS Mail to Microsoft Graph in a future update, but there is no published date to bank on. Waiting for that to arrive in time is a gamble.
What your business should do now
1. Find out who uses Apple Mail for work email. In many companies nobody quite knows — staff just set up their Mac the way they like. Ask around, and your IT provider can check EWS usage in the Microsoft 365 admin center to see exactly which mailboxes still connect through EWS.
2. Plan the migration — don't wait for breakage. The clean, supported move is the Outlook app, which is included with Microsoft 365 and works well on Mac. For staff who prefer Apple's Mail, the allow-list keeps it working until April 2027 while you plan — but treat that as a runway, not a fix. Set an internal deadline well before April: migrating email clients under pressure, with confused staff on a deadline, is exactly the kind of disruption a small bit of planning avoids.
3. Check for other EWS dependencies. Mail apps aren't the only things that can use EWS: older scanners that scan-to-email, legacy integrations, and some third-party tools connect this way too. The allow-list exercise is a good excuse to inventory everything that touches your mail system — many businesses discover integrations nobody remembers installing.
4. Use the moment to tighten up. While you're touching every Mac's mail setup, make sure multi-factor authentication is enforced on all accounts, review who has access to shared mailboxes, and confirm your email archiving and backup still cover the new clients. A protocol change is a natural checkpoint for email hygiene.
Why this hits UAE businesses unevenly
Macs are common in design studios, marketing agencies, consultancies and media companies across the UAE — exactly the profile of business where a silent email breakage on a Monday morning can stall client work for hours. If your office runs a mix of Macs and Windows PCs, the Windows users will notice nothing while the Mac users lose email, which makes the problem harder to diagnose from the outside. A five-minute audit of who syncs how, done this month, costs nothing; a scramble to fix a dozen broken Mac mailboxes in April will not be five minutes.
Microsoft's EWS shutdown is not a scare story — it's a scheduled, documented retirement with a clear deadline. Businesses that act early get a smooth, almost boring migration. Businesses that discover it in April get an emergency. If you'd like a quick check of your Microsoft 365 tenant — who is still on EWS, whether the allow-list is in place, and a migration plan for your Mac users — Request a quote, call us on (04) 359 4874, or message us on WhatsApp at +971 52 562 1946 for a free site survey — we'll audit your setup and make sure April 2027 arrives without a single lost email.
