PST folder Hierarchy

The article sheds light into how PST folder hierarchy is created.

Adding a PST to an existing profile doesn't create the all the Special Folders and looks as below:

We have the IPM Root, Common Views, Search Results, Deleted Items under the "Top of Personal Folders".
In short, the IPM subtree doesn't gets fully constructed which should include Outbox folder, Sent Items Folder and the Receive folder like the Inbox.

However, if the PST is set as the Default folder, we will see all the eight special folders that are part of IPM subtree are created and usually cannot be deleted in Outlook.