I had an issue where a user was having certain, not all but certain, emails moved into a folder called “Unwanted”. This was weird, as she never created said folder and Outlook doesn’t come with such a folder by default.
It took quite a while to sort it out. We removed rules, created new profiles and created new OST files, but to no avail. There were no server-side functions that would do this, either.
The hint came from the below article. Oddly enough, the article speaks of a “Junk” folder instead of “Unwanted”, but it turned out that the user had a Samsung phone.
Problem: Outlook creates a new folder called “Junk” and moves internal mail to the Junk folder.