Microsoft has confirmed that Exchange Web Services (EWS) in Exchange Online is approaching the end of its life. The shutdown starts in October 2026 and finishes with a complete and permanent disablement in April 2027. This change affects all Microsoft 365 Exchange Online tenants, while on-premises Exchange Server remains unaffected.
For IT admins, this is not a future problem. It is an active migration deadline.
Why Microsoft Is Shutting Down Exchange Web Services
Microsoft built EWS nearly two decades ago. It no longer meets modern security, reliability, or scalability standards. Over the years, Microsoft has shifted its own services and partners to Microsoft Graph, which now offers near-complete feature parity for most EWS workloads.
As a result, Microsoft is retiring EWS in Exchange Online in stages rather than cutting it off overnight.
Exchange Online EWS Shutdown Timeline and Key Dates
Now – September 2026
- EWS continues to work.
- Admins should audit usage and plan migrations.
- You can proactively configure EWS settings to avoid disruption.
October 1, 2026
- Microsoft begins tenant-by-tenant blocking.
- Tenants that take no action will have EWS disabled by default.
- Only explicitly allowed apps can continue using EWS.
April 1, 2027
- EWS is permanently shut down.
- Admin control over EWS is removed.
- No extensions, exceptions, or delays are allowed.
How Microsoft Will Disable EWS
Microsoft will control access using the EWSEnabled tenant setting and a new AppID Allow List.
| EWSEnabled Value | Before Oct 2026 | After Oct 2026 |
|---|---|---|
| True | All EWS allowed | Only apps in Allow List |
| False | All EWS blocked | All EWS blocked |
| Null (default) | All EWS allowed | Auto-changed to False |
If your tenant still uses the default Null value on October 1, 2026, Microsoft will automatically switch it to False, immediately blocking all EWS traffic.
What IT Admins Must Do Before Exchange Online EWS Shutdown
1. Audit EWS usage
- Check which apps, scripts, and integrations still depend on EWS.
- Hidden dependencies are common in legacy automation.
2. Migrate to Microsoft Graph
- Most EWS workloads already map cleanly to Graph APIs.
- Delaying migration increases outage risk during scream tests.
3. Configure EWSEnabled intentionally
- If you want EWS blocked, leave it disabled.
- If you still need EWS temporarily:
- Set
EWSEnabled = True - Maintain a strict AppID Allow List
- Set
4. Act before September 2026
- Tenants that configure settings early avoid automatic blocking.
- Early action prevents surprise service interruptions.
EWS Scream Tests: What IT Admins Need to Know
Microsoft will run short, temporary EWS shutdowns called scream tests. These tests expose undocumented dependencies before the final cutoff.
If your tenant already has EWSEnabled = True, Microsoft will exclude you from these tests. Otherwise, expect unexpected breakage that forces emergency fixes.
Important Clarifications for Hybrid and On-Prem Environments
- EWS is not retired for on-prem Exchange.
- Cloud mailboxes must move to Graph.
- Hybrid environments must handle API routing carefully.
- Exchange SE is required for Graph access in hybrid setups.
EWS in Exchange Online is not “going away someday.” It is on a fixed shutdown schedule with no extensions.
Admins who start now get clean migrations, predictable timelines, and zero downtime. Admins who delay risk broken workflows, angry users, and forced last-minute changes.
If your organization still relies on EWS, the safest move is clear: audit, migrate, and lock down your tenant well before October 2026.
