is there a concept of email authentication to send emails to register emails? If I know someone else's email address, and I sign up for datahub using someone else's email address, no one else can sign up using that email address

Currently, no there is not email registration confirmation. This is a super useful feature of course and we'd love to hear more about the use case on our feature request board (if you haven't already created). One way to work around is to set up Single Sign-On, which will indirectly ensure that the correct party is able to authenticate with DataHub application

@big-carpet-38439 would you please tell me How to set up single sign-on