Microsoft is retiring Exchange Web Services (EWS) in Exchange Online and will begin enforcing EWS restrictions starting October 1, 2026. Veeam has advised that customers using Veeam Backup for Microsoft 365 must take action within their Microsoft 365 tenant to ensure Exchange Online mailbox backups continue to operate successfully. At this time, Veeam's transition from EWS to Microsoft Graph is still in progress because Microsoft has not yet delivered all required Graph API functionality needed for incremental mailbox backups. Until that transition is complete, EWS access must remain available for Veeam Backup for Microsoft 365. Customer Action RequiredYour Microsoft 365 administrators must review and implement the guidance provided by Veeam before October 1, 2026, including:Configure Exchange Online so that EWS remains enabled (EwsEnabled = $true).Review and validate Microsoft's new EWSAllowedAppIDs allow list.Ensure the Veeam application IDs used for your backups are included in the EWS allow list. Customers that do not complete these steps may experience Exchange Online mailbox backup failures once Microsoft begins enforcing the EWS retirement changes. If backups stop because EWS access is blocked, mailbox protection gaps may occur until the required configuration changes are completed. For complete instructions, please review Veeam Knowledge Base article KB4820:What Microsoft's EWS Retirement Means for Your Veeam Backups If you have questions regarding your Veeam Backup for Microsoft 365 environment, please contact the Heartland Business Systems Data Center team. Thank you,Heartland Business SystemsData Center Teamdchelp@hbs.net