Using Classic Outlook on Windows for personal email, calendar, and contact management
check these instructions, I guess this will solve your problem. https://ut.service-now.com/sp?id=kb\_article&number=KB0012026
Outlook usually sends meeting requests to the Deleted Items folder when you respond to a meeting request. To change this setting and keep your meeting requests:
- Click the File tab, then Options, and then select Mail.
- Under the Send messages heading, make sure the Delete meeting requests and notifications from Inbox after responding checkbox is not selected.
- Click the OK button to close the dialog box.