Microsoft will begin retiring Exchange Web Services (EWS) in Exchange Online starting October 1, 2026. EWS is an older technology used by some email and calendar applications and is being replaced by more secure, modern connection methods.

As Microsoft rolls out this change, some people using older devices, unsupported operating systems, or outdated email and calendar applications may experience connectivity issues beginning in October and continuing over the following months.

What You Should Do

To help avoid disruptions:

• Update and keep your devices and operating systems current. 
• Update your email and calendar applications. 
• Use a Microsoft-supported Outlook client whenever possible. 
• Replace devices that can no longer run supported software.

Cornell is contacting account owners when available reporting tools indicate an application is currently connecting through EWS. However, not all affected devices and applications can be identified. If you use older hardware or software, do not assume you are unaffected because you have not received a notification.

Read additional details for more information about supported email clients, potentially affected devices, and recommended actions.

Need help? 

Contact the Information Technology Service Desk.