How do I transfer my personal folders from my old yahoo email address to my new yahoo one?

I had to set up a new yahoo email %26amp; was able to transfer my contacts list from my old address. I just cannot figure out how to transfer the personal folders I created in my old address without having to email each individual one.

How do I transfer my personal folders from my old yahoo email address to my new yahoo one?
After I transeferred by old address book to my new one, it automatically transferred all of my folders.