This post is a part of our EWS (Exchange Web Services) to Microsoft Graph Migration Guide Series.
In 2018, we announced that we were no longer making feature updates to Exchange Web Services (EWS) in Exchange Online, and we advised developers to move to Microsoft Graph.
Today, we are announcing that on October 1, 2026, we will start blocking EWS requests from non-Microsoft apps to Exchange Online.
While the EWS components of the service will continue to receive security updates and certain non-security updates, product design and features will remain unchanged. This change also applies to the EWS SDKs for Java and .NET, as well.
Despite today’s announcement, EWS is still available and supported for use in production environments. But we strongly suggest migrating to Microsoft Graph to access Exchange Online data and gain access to the latest features and functionality.
Today’s announcement and the retirement of EWS apply only to Microsoft 365 and Exchange Online (all environments); there are no changes to EWS in Exchange Server. Further, the changes in Exchange Online do not affect Outlook for Windows or Mac, Teams, or any other Microsoft product.
Migrating Applications to Microsoft Graph
We know there are several feature gaps between EWS and Microsoft Graph, and though the list below is not exhaustive, these are the gaps most frequently reported to us by developers:
- Access to Archive Mailboxes – We are working on delivering access to archive mailboxes via Microsoft Graph and will provide an updated timeline in the coming months.
- Folder Associated Information / User Configuration – We are working on these features and will provide an updated timeline in the coming months.
- Exchange Online Management – We are investigating solutions for this and will provide an updated timeline in the coming months.
- Access to Public Folders – We are reviewing the need to provide third-party app access to Exchange Online public folders via the Graph API and are interested in hearing from customers and partners who build solutions that use public folders, other than backup and restore solutions. If you are willing to share details on how you use EWS with public folders, we’d love to hear from you, and you can reach us at EWSandPFfeedback@microsoft.com.
We know there are other gaps not listed above, and we continue to work on closing them, but it’s possible some functionality will not make it to Microsoft Graph. We encourage you to provide feedback to us, keep a close eye on the What’s new in Microsoft Graph page, and explore alternatives for functionality or features not available in Microsoft Graph.
Next Steps
The retirement of these APIs follows our service deprecation policies. We understand changes like this may cause some inconvenience, but we are confident it will ensure more secure, reliable, and performant experiences.
We will publish regular communications as we progress towards this deadline to aid affected tenants in identifying EWS usage. We encourage all customers to monitor Message Center and this blog for related content.
Thank you in advance for updating and opening your apps to a wider range of useful and intelligent features on Microsoft Graph. We are extremely excited about the growing opportunities that Microsoft Graph offers to developers, and we remain fully committed to our journey to empower developers to access Microsoft 365 data with the most modern features and tools.
The Exchange Team
