How to Recover a Deleted Folder in Outlook
Summary
If you mistakenly delete a folder from your Outlook inbox, it is possible to recover it.
Instructions
This should work on Client installed version of Outlook or Web version of Outlook.
1. Open Outlook and look at your Inbox on the left. You should find a "Deleted Items" option. It's most likely in the collapsed view.
2. You'll need to click the chevron so it points down to find your missing folder.