I too had the same problem. I remember creating a blogger name once upon a time, but had forgotten my login blog name to sign into it. Since wanting to help you out, I found mine out at same time.
I'm pretty sure you can use any email address. Try it you never know. GL.
edit: Just checked and it's not possible (I thought they could get it by ip address). You would need the email address you used in creating the blog. In this case, just contact them and explain you no longer have access to your old (forgotten) email address.