The system will create a Contact box which requires Email:
It is not possible to to use the system without collecting an email address.
If you do require the Email address in Standard Questions, there will not be a Contact box.
When your registrant completes a registration and is presented with a Review page to verify and/or edit information, a Contact box is always shown - regardless of the use of the Standard question for Email.
The concept of 'Contact' is important because that is the email address used to send a confirmation - even if multiple registrants are present with different email addresses - only the first email entered will be sent a confirmation.
On the review page, the contact box may be edited to change that imputed email and may be any valid email address, including an email address not present in the registration.