I don't know the history of OpenID at all, and don't know the history of email well enough to comment, but I suspect email didn't become a common word overnight

I don't know the history of OpenID at all, and don't know the history of email well enough to comment, but I suspect email didn't become a common word overnight, and I doubt most people would know how to use a client that asks them for SMTP settings these days (they expect to just visit gmail.com and see messages, or maybe at the most complicated install Thunderbird, enter their username and password, and wait while it says "autoconfiguring" for a bit).