UsersWP Restrict User Signups Addon GPL Overview:

The Restrict User Signups add-on is your site gatekeeper. It will stop undesired users from signing up to your website.

Restrict User Signups Settings

You have the option to disable username restrictions and only restrict email domains.

Restricting usernames

• You may Disable Spaces in your Username.
• Restrict Full Match and Partial Match usernames. You can do that by entering a comma-separated list of undesired usernames.

Restricting email domains

• You have the option to disable email domain restrictions and only restrict usernames.
• With one click you can restrict 3215 disposable email domains that we identified for you.
• Those are the most used by spammers. You can find the full list here.
• You also have the option to block any unwanted email domain.
• You can do that by entering a comma-separated list of undesired domains.

Allowed email domains

Finally, you have the option to only accept signup only from users with a specified domain. If for example, you want to limit registration to users with an email address from your university, or your company, now you can!