How do I create folders inside of folders in my email account?

I want to add a folder inside of another folder that already exists. How Do I do that?

How do I create folders inside of folders in my email account?
Yahoo doesn't allow "sub" folders (unfortunately)-----but they have promised (?) to consider adding that feature in the future-----just don't hold your breath while waiting.
Reply:go to yahoo.and log in.go to inbox and search.you can see floders.copy a floder and paste it.