OpenId has been going on for some time now. I think the third version was released about 5 years ago.
The idea is not bad: you have a main account that you can use to login to other places on the web / mobile apps without having to create a new account. You can choose what the new site “sees” (e.g. only email and not the full name).
It was all the rage a while ago but to me it never seemed to take off. Also the “login with Facebook” or Google similar functionality kinda became the de facto way of having a SSO (single sign on).
Unless your punting email is on a service that acts like an openid provider and you want to link it with your account, it’s probably a bad idea to use it. You don’t want this account to be linked to your real google / Microsoft / yahoo account.