A new option has been implemented that affects the "Login via email" field: it is the "Email restriction" option, which allows restricting the emails addresses that users can register with in the promotion. Specifically, this option allows you to apply three different types of restrictions: 

1. By domain: this option allows only emails from specific domains to register in the promotion. In this case, you must specify the allowed domains that users will be able to use to participate in the promotion.
2. By a closed list: allows uploading a set of codes with up to two million emails, so that when the user enters the email in the field, the system will validate it against this code set. 
3. By Mailchimp subscriber: this option limits participation to users who belong to a Mailchimp subscriber list. In this way, when the user registers, the system verifies in real-time if the email entered by the user is in the subscriber list linked to the promotion, and if the user is not a subscriber, a message will appear encouraging them to subscribe.