A new application protection policy setting has been introduced in Intune to let you manage Outlook Mobile notification.
With this new setting, administrator can define if notification from Outlook Mobile (email and calendar) can be (or not) by displayed on the lock screen – this is available for both Android and iOS devices, including wearable ones (such as Smart Watch).
To configure this setting, logon to either your Azure portal, and go to the Intune\Client apps blade (https://portal.azure.com/) or Device Management portal and go to the Apps blade (https://devicemanagement.microsoft.com/)
Then go to the App protection policies and create a new application policy (or edit the existing one if any) for Android or iOS and select Outlook for the Apps
The setting to manage Outlook notification is available at the Data protection step (bottom of the configuration page)
The available options are:
To ensure this policy settings is applied you need to ensure you are running at least Outlook Mobile 4.83.0