Do I HAVE to upgrade my email?

I don't want to be upgraded to Yahoo Mail Beta!!! I have tried it twice before, and it DOUBLES the time it takes now to pull my emails in and read them. And because I get so much junk mail, I prefer to use my preview pane...from what I understand, I will still be able to preview my emails, but they will all be "scrolled together". I want to see and delete one at a time. I feel that I am being forced to change programs, when the one I have now is just exactly what I want. :O(