Unlike being able to start Outlook via a a scheduled task, the Task Scheduler in Windows sadly doesn’t have a “close application” option. However, you can use a simple PowerShell or vbs-script for it to close Outlook gracefully or even kill the process (as a failsafe method).
By using a script to close Outlook, you can for instance make sure that Outlook is closed when a(n automated) backup is being made so that the pst-files are no longer locked and the backup process doesn’t fail.
The script examples in this guide can either be ran as a standalone PowerShell or vbs-script, be scheduled, or be part of a larger script such as logon or logoff scripts.
Continue reading: Closing Outlook via a (scheduled) PowerShell script