Outlook may not always recognize the correct folders when the IMAP mailbox is based on a “root structure” where all the other mail folders are created under the default Inbox folder.
The result is that Outlook will ignore the already existing Sent Items and Deleted Items folder on the server and create some local ones of its own.
When you set the “Root folder path” option in your account settings, Outlook will usually recognize the correct folders.
You can root your mailbox in the following way:
1. File-> Account Settings-> Account Settings…
2. Double click on your IMAP account.
3. Button: More Options…
4. Tab: Advanced
5. Option: Root folder path
6. Usually setting this to “Inbox” will do the trick.
7. OK yourself out all of the opened dialogs.
For more details please refer the below link :