For email list there are two actions to choose.
- Allow only user's input match an email or email domain name in the list then it will be allowed to submit while other input will be blocked ( disable notification ). You may use this to make a only invited users can register form.
- Block means if users' input match an email or email domain name in the list then it will be blocked to submit ( disable notification ). You may use this to prevent spam comments or block competitor's email.
The following example use emails as a white list. It means only emails which added to email list allowed to submit form.