I am very happy that I finally had the nerve last night to try this upgrade and after about 4 hours I successfully did it.
Now I always read my emails every day and then put them in the trash and then emptied the trash. But now it is loading old emails 42 at a time which I know I have read and deleted and emptied before.
I spent some time this morning deleting them again but now realize I have 9,976 emails that keep uploading when I open my email and this is going to take me forever to get rid of them all.
What can I do?