Microsoft is disabling Exchange Web Services (EWS) in Exchange Online by default on October 1, 2026, with permanent shutdown on April 1, 2027.
What Veeam is doing
Veeam is actively transitioning Exchange backup from EWS to Microsoft Graph. However, Microsoft has not yet completed all the Graph API capabilities required for incremental backup. Until that gap is closed, EWS must remain accessible for Exchange Online backups to continue. An updated product release supporting the full transition is in development.
What you need to do before October 1, 2026
- Most tenants have EWSEnabled at its default value of $null. This is not the same as $true — on October 1, Microsoft will automatically flip $null to $false, blocking EWS for all apps. You need to explicitly set it to $true before that happens.
- Review EWS usage in the Microsoft 365 Admin Center and add your Veeam app IDs to EWSAllowedAppIDs. Microsoft may pre-populate this list, but you are responsible for validating it.
- Grant the required Microsoft Graph permissions to your Veeam app registrations in Entra ID.
- Upgrade to the updated product release when available.
EWS will be automatically disabled for your tenant and your backups will start failing. You can re-enable EWS after the fact — but you will have a backup gap, and the first backup after re-enabling will be a full sync instead of incremental.
More information
For full instructions, see KB4820