Allowed email domains
This feature gives you the option to allow the registration of users that use a specific domain for their email address. For example, you can allow the registration of students using their university email address or users using an email address of an organization or company.
How to use this feature?
To enable it, you need to go to Settings -> General and find the "Allowed email domains" field. In there, you need to write the email domains that you'd like to add for your users.
Keep in mind that you need to push enter after each email domain name so that it's saved..
If you want to allow all the email domains to be able to register on your site, just leave the field empty.