EWS Retirement: What CRM On‑Premises 9.x Users Need to Know to Prepare
How the October 1, 2026 EWS Block Impacts CRM On-Premises 9.x
Starting October 1, 2026, Microsoft will begin blocking Exchange Web Services (EWS) in Exchange Online. EWS is an older integration method that’s been around for years, and Microsoft has been clear that it’s reaching the end of the road.
If you’re running Dynamics CRM / Dynamics 365 on‑premises 9.x and using Exchange Online, this matters more than it might sound at first glance.
Because when EWS goes away, core CRM email and calendar functionality can go with it. And October isn’t that far away anymore.
What’s Actually Changing?
Here’s the short version:
- On October 1, 2026, Microsoft will start blocking EWS connections in Exchange Online
- If nothing is done, EWS access will be turned off by default
- On April 1, 2027, EWS will be permanently retired with no option to re‑enable it
This change applies only to Exchange Online. If you’re running Exchange fully on‑premises, you’re not affected. But many organizations run a hybrid setup – CRM on‑premises with Exchange Online – and that’s where the risk comes in.
Why CRM On‑Premises 9.x Is Impacted
CRM on‑premises 9.x was built when EWS was the standard way to connect to Exchange. As a result, many environments still rely on it for:
- Server‑side email and calendar synchronization
- Mailbox processing
- Activity tracking between CRM and Outlook
Once Exchange Online blocks EWS, those integrations don’t just degrade nicely. Mailboxes can stop processing. Emails stop tracking. Appointments don’t sync. And from the user’s perspective, it often looks like “CRM is broken” without an obvious reason why.
Our CRM Is On‑Prem – Are We Affected?
This is a common question, and the answer is yes, if Exchange Online is involved.
Microsoft’s change isn’t about where CRM lives. It’s about what Exchange Online allows. Any application connecting to Exchange Online using EWS, cloud or on‑prem, is impacted.
So, if your setup is:
- CRM on‑premises
- Exchange Online
…this applies to you.
Why Microsoft Is Making This Change Now
This isn’t a surprise move, Microsoft has been signaling the retirement of EWS for years, and recent security concerns have accelerated the timeline. Their long‑term direction is Microsoft Graph, a modern integration platform that’s more secure and actively developed.
Dynamics 365 Online already uses this modern approach. CRM on‑premises 9.x does not.
The Timing Challenge
Although October may seem far away, migrations take time, especially when planning, testing, data validation, and change management are done correctly.
Microsoft has also indicated it may perform temporary EWS disablements (“scream tests”) ahead of October 1 to help organizations discover hidden dependencies. Waiting increases the risk of unexpected service interruptions.
By starting now, organizations gain:
- Control over timing
- A smoother transition for users
- The opportunity to modernize, not just react
Turning a Deadline Into an Opportunity
The EWS retirement is not simply a technical change, it’s a strategic moment. Many customers are using this milestone to:
- Retire aging infrastructure
- Simplify their CRM and Microsoft 365 architecture
- Position themselves for future innovation with Dynamics 365 and Power Platform
Rather than investing effort in short‑term workarounds, moving to Dynamics 365 Online provides a future‑proof path that aligns with Microsoft’s long‑term roadmap.
Why Many Customers Are Choosing Dynamics 365 Online
For most organizations, this isn’t just about avoiding a deadline. It’s about simplifying their environment and aligning with where Microsoft is investing.
Moving to Dynamics 365 Online means:
- No dependency on deprecated Exchange technologies
- Automatic updates and security enhancements
- Better integration with Microsoft 365, Teams, and Power Platform
- Less infrastructure to maintain
- Access to Microsoft’s latest capabilities, including Copilot
It removes uncertainty and puts CRM back on solid footing.
Avoid Disruption and Start Planning Today
If your environment includes CRM on‑premises 9.x alongside Exchange Online, this change needs attention in the near term.
With the deadline approaching, starting planning now is important to ensure you have options and avoid last‑minute disruption. Reach out to the Stoneridge team if you need assistance planning your transition.
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