If you cannot see your folders in Yahoo!, it is possible that you need to click the triangular arrow that points to the word Folders in the left column of the screen.
As you can see from this image above, when you don’t have this accordion arrow open, you cannot see your Sane folders.
When you click the arrow (as seen below), it will point down instead of to the right, and your list of Yahoo! folders will be seen.
If this does not help, please open a Support request so we can look into this further.