Microsoft is retiring Exchange Web Services (EWS) for Exchange Online. Commvault supports Microsoft Graph for eligible Exchange Online workloads, but the transition requirements vary by Commvault deployment, release, workload, and tenant configuration.
This page explains the key dates, available transition paths, and configuration considerations to help reduce the risk of interruption to supported Exchange Online protection.
Important
Microsoft and Commvault capabilities, dates, permissions, and transition behavior may change. Before making changes, confirm the current requirements in the Commvault documentation for your deployment and release.
Why This Matters
If your environment still relies on EWS when Microsoft disables it, affected Exchange Online backup operations may stop until you enable a supported Microsoft Graph configuration or restore approved temporary EWS access.
Review both paths and choose the approach that best matches your environment.
Dates to Know
| Date | Current Guidance |
|---|---|
| October 1, 2026 | Microsoft plans to begin disabling EWS in Exchange Online. The timing and behavior may depend on tenant configuration and Microsoft's phased rollout. |
| April 1, 2027 | Microsoft plans to complete the permanent retirement of EWS in Exchange Online. |
Microsoft's current guidance says EWS will be disabled in Exchange Online beginning on October 1, 2026, and identifies April 1, 2027, as the completion of the retirement process. Administrators should confirm the latest Microsoft timeline before making tenant changes.
Your Two Paths Forward
Find Your Release
Commvault Cloud (SaaS)
| Mailbox Type | September 15, 2026 Release | Notes |
|---|---|---|
| Primary mailbox | Supported | |
| Archive mailbox | Supported | |
| Shared mailbox | Supported | |
| Group mailbox | Supported (Early access) | Global Reader role required. SLA is not impacted. |
| Public folder | Not supported | Microsoft does not provide public folder APIs in Graph. |
Commvault Software (Self-hosted)
| Mailbox Type | 11.44 (September 1, 2026) | 11.44 (October 6, 2026) |
|---|---|---|
| Primary mailbox | Supported | Supported |
| Archive mailbox | Supported | Supported |
| Shared mailbox | Supported | Supported |
| Group mailbox | Not supported | Supported (Early Access) |
| Public folder | Not supported | Not supported |
Commvault records a pending reason for every skipped or failed mailbox.
Important
Commvault Software 11.44 releases after Microsoft begins blocking EWS.
If you run Commvault software and protect Microsoft 365 Group mailboxes, you cannot complete your transition before October 1, 2026. Extend EWS to keep your backups running, then upgrade to 11.44.30 and finish your transition.