Microsoft is deprecating its cross-platform Exchange Web Services (EWS) API starting October 1, 2026, meaning users will no longer be able to access their emails and contacts from Exchange Online.
When Microsoft retires the API, users who rely on EWS to retrieve their messages, meetings, and other elements from other inboxes will find that it no longer works.
These changes apply to Microsoft365 and Exchange Online environments. Outlook, Teams, EWS in Exchange Server and other Microsoft products continue to work as before.
Bridging the gap in Microsoft Graph functions
This news is not unexpected, as the company announced that EWS would not benefit from new features in 2018. Now the company has announced that in three years, EWS will block requests from non-Microsoft apps to Exchange Online.
Instead, the company has advised all users to migrate to Microsoft Graph to ensure smooth continuity, despite acknowledging some features it lacks that EWS users have enjoyed for years.
First released in 2015, Microsoft Graph connects multiple services and devices together, similar to the way EWS works. The main difference is that Microsoft Graph APIs are REST-based, while EWS APIs are SOAP-based. According to Microsoft, this translates into faster JSON serialization and lower network usage.
“Despite today’s announcement, EWS is still available and supported for use in production environments,” the Microsoft Exchange team said. “But we strongly recommend migrating to Microsoft Graph to access Exchange Online data and gain access to the latest features and functionality.”
Between now and the cutoff date in 2026, Microsoft will push security updates and some non-security features to a handful of EWS components. But overall, the platform won’t benefit from major changes.
However, Microsoft also acknowledged the ‘feature gaps’ between EWS and Graph, adding that it would work to expand the list of features that Graph users can enjoy in the coming years. However, not all features may be migrated.
These features include access to archive mailboxes, information about folder associations and user configuration, online exchange management, and access to public folders.