I'm the same. An email address isn't an identity. Some people use many email addresses and so could create many accounts. With one email address they can still

I'm the same. An email address isn't an identity. Some people use many email addresses and so could create many accounts. With one email address they can still use the '+blahblah' method to sign up unlimited times, unless you prevent that which would annoy people who use it legitimately for filtering. Some people have a garbage or throwaway email account that they sign up for everything with, and only ever look at to find the confirmation emails. If people don't want to give you a valid email then there's no reason to be sending them anything.