How to make email email field in registration form optional?

Hi,

I would change the attribution of the email field of the registration form to NOT_MANDATORY, aka I would create a registration form without email field.

Is it possible? If yes, how? I’ve tried to remove the email field from the registration form, but it’s not possible.

Having an email address is mandatory for registrants and cannot be disabled due to how Indico works, in order to send notifications to them, keep track of their actions, etc.