Updated advisory as of June 2026. We will continue to provide new updates as we see further developments and updates from Microsoft around their transition. - Commvault Support & Community team
At Commvault, we are committed to ensuring your data remains resilient and your transitions remain seamless. We are closely monitoring Microsoft’s retirement of Exchange Web Services (EWS) in Exchange Online and are already engineering the path forward for your backup environment.
What is Changing?
Microsoft is transitioning from the 20-year-old EWS architecture to the modern, REST-based Microsoft Graph API. This shift enhances security via OAuth-based authentication and provides a more unified architecture across Microsoft 365.
The Timeline
Per Microsoft, below is the revised planned transition timeline for EWS. They removed the previously communicated June milestone to phase out some EWS access.
- October 1, 2026: Phased disablement of EWS begins (tenant-controlled).
- April 1, 2027: EWS permanently retired for all Exchange Online tenants.
⚠️ IMPORTANT: This change applies only to Exchange Online. On-premises Exchange Server environments are not impacted by this deprecation.
Commvault Milestone Details
We understand that your backup continuity is non-negotiable. Commvault is developing a robust, Graph API-based Exchange backup solution designed to bridge existing API gaps while maintaining the high standards of recovery you expect.
Planned Availability: Summer 2026 Target Release 11.44 LTS deployment models supported for both SaaS (Metallic) and Software. Our timeline ensures your environment is "Graph-ready" well before Microsoft begins the phased disablement in October 2026.
Dependency on the Microsoft Ecosystem
As a Microsoft partner, Commvault’s development timeline is inextricably linked to Microsoft’s API release schedule. While Graph is the future, Microsoft has acknowledged that it does not yet have full feature parity with EWS.
What this means for you:
- Shared Timelines: Our delivery of 11.44 LTS depends on Microsoft releasing stable, production-ready versions of the necessary Graph endpoints.
- Gap Closure: We are working directly with Microsoft to ensure they address "feature gaps" (such as Archive Mailboxes, Public Folders, and advanced metadata) so that your backup fidelity is not compromised.
- Proactive Adaptation: If Microsoft shifts their roadmap or delays critical API features, Commvault will adjust our engineering efforts to keep your data protected using the most secure methods available.
Recommended Actions for Administrators
While the transition is still a ways off, there is one key area to keep on your radar:
Permissions Prep: Moving to Graph will require reauthorizing Azure AD applications and granting new OAuth scopes. We will provide detailed "how-to" documentation closer to the October milestone.
Stay Tuned
We will continue to share updates, timelines, and guidance here and through our KB.
For full Microsoft guidance, take a look at this blog post from their Exchange team and this Microsoft Learn article.
As always, don’t hesitate to post questions here or reach out to your account team.
