For some reason Yahoo says my email doesn't exist. Why?

Answer 1

Yes they have deleted your account so you cannot appeal

cheaper than employing a real person to take any action on an appeal

I was Using One account when it said join get 100 points  had only one account and tried to use last pass to login, and it said Email address unknown

Answer 2

Yahoo mail accounts 

Answer 3

It could be several things and only you will know.

1. Wrong password, reset it.

2. You were suspended.

3. The account was deleted due to inactivity.

Answer 4

Click on the envelope on this or any Yahoo page. Since you are logged in here and posting it means you are logged into your email account.

Answer 5

Maybe it doesn't exist