Configuring Office 365 for scheduling using a service account

The Secure Scheduler for Exchange feature previously supported the use of a service account with the Application Impersonation role. However, Application Impersonation role assignment to service accounts has been deprecated by Microsoft. From May 2024, Microsoft prevented new Application Impersonation role assignments. From February 2025, this role was removed completely (for more information, see Microsoft's announcement). For Office 365, all new Secure Scheduler for Exchange deployments must use the alternative option using application permissions, and all existing deployments must be updated to enable this option as soon as possible.