Microsoft Exchange Web Services (EWS) Retired October 1, 2026
Oct 1, 2026Microsoft is retiring Exchange Web Services (EWS) in Exchange Online on October 1, 2026 and will no longer be available for use at the university. After that date, applications and email clients that still use EWS will no longer be able to connect to Microsoft 365 mailboxes. Learn more on Microsoft's website.
What is EWS?
Exchange Web Services (EWS) is an older technology used by some applications to access Exchange Online services such as:
- Calendars
- Contacts
- Mailbox automations
- Service accounts and workflow integrations
While most Microsoft 365 applications have already transitioned to modern technologies, some third-party applications, custom integrations and automated processes may still rely on EWS.
Who Is Not Impacted?
Most Outlook users will NOT be affected. Modern versions of Microsoft Outlook and Microsoft 365 applications do not rely on EWS.
If you use any of the following, no action is needed:
- Outlook for Windows
- New Outlook for Mac
- Outlook on the web
- Outlook Mobile
Who Is Impacted?
Apple Mail Users
Apple Mail uses EWS when connected to a Microsoft 365 or Exchange Online mailbox. After EWS retirement, Apple Mail will no longer be able to access Exchange Online email, calendar, contacts or other mailbox data.
Solution: Users should migrate to Microsoft Outlook for Mac or another supported Microsoft 365 client.
UPDATE Oct. 2, 2026: Apple is actively working to update its native applications to use the Microsoft Graph API; however, those updates are not yet available as of October 1, and Apple has not provided an estimated release date.
To give users additional time to transition to a supported Microsoft 365 application, and to allow time for Apple to release the necessary updates to its native apps, ISS is granting a temporary exception that permits Apple Mail, Calendar, and Contacts to continue accessing university email services until EWS is fully retired on April 1, 2027. This exception cannot be extended beyond that date.
We strongly encourage users to migrate to a supported Microsoft 365 application as soon as possible rather than waiting until the retirement deadline.
Please note that no extensions will be granted for other applications or services that rely on EWS.
Legacy Outlook for Mac Users
Legacy Outlook for Mac relies on EWS connectivity and will no longer function with Exchange Online after EWS retirement.
Solution: Users should switch to New Outlook for Mac, which uses modern Microsoft 365 technologies and does not depend on EWS.
Other Applications and Integrations
EWS-dependent solutions may experience service interruptions as Microsoft ends support such as:
- Third-party applications
- Room reservation integrations
- Custom solutions
- Mobile apps
- Calendar tools
- CRM integrations
- Automation processes
Solution: If you use an application that interacts with your Microsoft 365 mailbox, calendar, contacts or other Exchange Online services, verify with the application owner or vendor that it supports modern authentication technologies and/or Microsoft Graph.
Action Required
Apple Mail users: Transition to Outlook for Mac.
Legacy Outlook for Mac users: Switch to New Outlook for Mac.
Application owners: Review and update any applications, scripts, services, or integrations that use EWS.
If you have questions about whether an application or email client uses EWS, please contact the Service Desk.
