You should not store every email used on the registration forum
How else can we identify you, or send you a message if need be? What’s the point of having multiple identities in one forum?
the other name was not accepted and I cannot see how I can delete an email for a user non existing….
Of course, none of the regular members have the ability to delete an account in this forum. It would be disastrous if we allow that. But we can delete that account easily if you provide us with the email address that shows up the error “email already exist”.
the registration is like wordpress.org, a bit buggy 🙁
This is not a bug, it has been industry standard for a long, long time. And for good reasons.