As some of your users may share an email address, we've updated our system so that you can add multiple users using the same email address
In the Admin area under 'Users' -> 'Add Single User'. If you were to attempt to add a new user using the same email address as a user already in the system, you're greeted with a message that warns you that the Email is already in use.
The message lists the users currently using this email address and warns you that adding duplicate users with the same email address will potentially allow the users to access each other's accounts, change each other's personal information, and reset each other's passwords.
If you understand the risks outlined you can continue adding this user by checking the box to confirm and clicking "Add User"