There does seem to be a way. But it's very repetitive and like the new MS Outlook, it's very, very annoying.
When the new email program launches, seek out "Help" in the menu at the top.
There should be something at the very end that says "Go to Old Outlook" or something similar.
Click on that, click off all the garbage that comes up, and then try launching your old email program again.
It should come back, but every time you turn on your computer or want to access this program, you'll need to do this again.
It's a pain in the you-know-what but worth it, given how awful the new Outlook is.
I think I will go into Bill Gates house and change all his furniture without asking. If he can do it to me, I should be able to do it to him...