Updated advisory as of Aug. 19. 2026. We will continue to provide new updates and guidance as we get closer to the September Commvault release dates and Microsoft’s October milestone to begin the phased disablement of EWS. - Commvault Support & Community team
As shared previously, Microsoft has announced the retirement of Exchange Web Services (EWS) in Exchange Online, with phased EWS disablement scheduled to begin on October 1, 2026.
For our customers and partners backing up Microsoft 365 and Exchange Online in your environments, please review closely the following KB articles for our most current guidance about steps to take to maintain continuity in your Exchange Online backups and further background on Commvault’s plans for Microsoft Graph support.
- (New) Maintaining Exchange Web Services (EWS) access for Exchange Online before planned End of Life. This article describes steps to take to maintain EWS access for your Commvault backups during Microsoft's EWS phased retirement period and before its scheduled full retirement in the spring of 2027.
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Transitioning to the Microsoft Graph API for M365 - Exchange Online This earlier article contains detailed information about Commvault's Microsoft Graph support plans, requirements, and preparation steps.
We suggest clicking “subscribe for updates” and we will also continue to provide a heads up here in the Community and through direct outreach to impacted customers in the fall.
Recap: What is Changing?
Microsoft is making a phased transition 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.
Commvault is transitioning applicable Exchange Online functionality to Microsoft Graph. Commvault will continue to use EWS for certain Exchange Online data protection and recovery operations after October, specifically for those objects without current parity with the Graph API. Because Microsoft Graph does not yet support every Exchange Online workload, Commvault will use a hybrid transport model until the Microsoft transition is complete.
Microsoft EWS Phased Retirement Timeline
Per Microsoft, below is the revised planned transition timeline for EWS.
- October 1, 2026: Phased disablement of EWS begins
- April 1, 2027: EWS permanent retirement for all Exchange Online tenants.
⚠️ IMPORTANT: This change applies only to Exchange Online. On-premises Exchange Server environments are not impacted by this deprecation.
Planned Commvault Milestones & Timings
We understand that your backup continuity is non-negotiable. Our hybrid approach and timeline is intended to ensure your environment is "Graph-ready" before Microsoft begins the phased disablement in October 2026 and also that there is continuity for workloads not yet fully supported by Graph.
Recommended Actions for Administrators to Prepare
Please review the two KB articles above for detailed instructions about actions to take depending on your deployment type.
- Microsoft requires that organizations that require EWS after October 1 (including Commvault customers) configure a setting that allows administrators to explicitly specify which applications can continue accessing EWS based on their Microsoft Entra Application ID. Full details here.
- Depending on your deployment model, verify or reauthorize the Azure apps being used for the workload have the appropriate permissions set to use the Graph API. Impacted on-premise software customers will need to upgrade to 11.44 and Commvault will release a hotfix cycle in September. Further details here.
For Commvault SaaS (Metallic) customers, Commvault will automatically enable the Graph API as the primary mode of transport beginning in September. From the customer side, the only action that should need to be taken is verification of permissions against the Azure applications you have configured. A small number of customers using legacy single-tenant Azure apps may need to do additional configuration of permissions as noted in the KB article, and you will receive a notification in-app.
For self-hosted / on-premises software customers with Exchange Online, Commvault plans to release a hotfix cycle for 11.44 in September where, similar to SaaS, the Graph API will be enabled by default. To continue protecting your Exchange Online mailboxes after Microsoft retires EWS in April 2027, you will need to upgrade to Commvault 11.44 or later. Once deployed, the only action required by the customer is to verify the Azure apps being used for the workload have the appropriate permissions to use the Graph API.
Note: 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 and some decisions are still in progress. This is an ongoing process and subject to further changes as Microsoft continues to evolve their release plans and dates.
For full Microsoft guidance, take a look at this blog post from their Exchange team and this Microsoft Learn article.
Stay Tuned!
We will continue to share updates, timelines, and guidance here and through the KB articles noted above.
As always, don’t hesitate to post questions here or reach out to your success team for advice.
