It is possible to prevent visitors from subscribing with a disposable email (a fake email that will be used only once). We will use the WisePops JS callbacks feature to download a list of disposable email providers, and ensure that the listed domains are not used in the email field.
Step 1:
From our editor, create a new JS callback listening for the event Before popup display:
Step 2:
Copy/paste the following snippet as the script of the created callback:
// Get list of disposable email domains
var xhr = new XMLHttpRequest();
xhr.open('GET', 'https://raw.githubusercontent.com/ivolo/disposable-email-domains/master/index.json', true);
xhr.responseType = 'json';
xhr.onload = function () {
if (xhr.status === 200) {
window.wisepopsDisposableEmailDomains = xhr.response;
}
};
xhr.send();
When the popup is being displayed, we will load the list of disposable email providers from the open source project ivolo/disposable-email-domains.
This fetched list is loaded asynchronously - meaning that it won't delay the display of the popup.
Step 3:
Create a second callback listening for the Before form submit event.
Step 4:
Copy/paste the following snippet into the callback's script:
// Prevent sign-up with a disposable email
// This script uses the list fetched by the before-popup-display callback
var isDisposableEmail = false;
var emailField = event.target.elements['email'];
var emailParts = emailField.value.split('@');
if (emailParts.length === 2 && window.wisepopsDisposableEmailDomains) {
isDisposableEmail = window.wisepopsDisposableEmailDomains.indexOf(emailParts[1]) > -1;
}
if (isDisposableEmail) {
emailField.setCustomValidity('This domain is not allowed');
} else {
emailField.setCustomValidity('');
}
Here we will try to match the filled email domain against the previously fetched lists. If a match is found, we will display this error message: "This domain is not allowed.”
You can learn more about how to write custom validations for your forms here.
You're done! You final config should look like this: