But an email address is the only thing that is close to 100% going to be unique to you and nobody else. JohnSmith? Millions of them. InitSurname? Millions of them. XYZyyymmdd? Thousands of them. youremail@yourdomaim? ONE. By definition.
I had to set up a user list for just 30ish people. I hadn't got past 'A' before getting a clash with almost all naming methodologies.