Limiting Sign-Ups to Trusted Email Services

[Looper]

Many people are using temporary email addresses to sign up on my website. I want to stop this and only allow well-known email services like Gmail, Yahoo, and Outlook. How can I do that?

[leemahoney3]

The following hook will do the trick (will also run when a client tries to update their email later on)

<?php

declare(strict_types=1);

add_hook('ClientDetailsValidation', 1, function ($params) {
    $allowedProviders = [
        'gmail.com',
        'outlook.com',
        'hotmail.com',
        'icloud.com',
    ];

    $explodedEmail = array_filter(explode('@', $params['email']));
    $emailProvider = $explodedEmail[1];

    if (!in_array($emailProvider, $allowedProviders, true)) {
        return 'Sorry, your email address provider is not whitelisted. Please choose another.';
    }
});

Won't work for user emails though, and WHMCS doesn't seem to hook on to that annoyingly.

[Looper]

5 hours ago, leemahoney3 said:

The following hook will do the trick

I'm new to this. Could you please provide guidance on how to create this hook and where to add it?

[Remitur]

Look at this hook: it doesn't limit the registration to whitelisted domains, but prevent the usage of disposable addresses:

https://domainregister.international/index.php/knowledgebase/696/Check-User-Data-for-Better-WHMCS-Security.html

[leemahoney3]

1 hour ago, Remitur said:

Look at this hook: it doesn't limit the registration to whitelisted domains, but prevent the usage of disposable addresses:

https://domainregister.international/index.php/knowledgebase/696/Check-User-Data-for-Better-WHMCS-Security.html

That relies on a call to a third party. If that's what the OP wants, then cool.

20 hours ago, Looper said:

I'm new to this. Could you please provide guidance on how to create this hook and where to add it?

Just create a PHP file in [YOUR WHMCS ROOT]/includes/hooks (e.g. RestrictClientEmailHosts.php)

[Looper]

7 hours ago, Remitur said:

Look at this hook: it doesn't limit the registration to whitelisted domains, but prevent the usage of disposable addresses:

https://domainregister.international/index.php/knowledgebase/696/Check-User-Data-for-Better-WHMCS-Security.html

Thanks, man! It worked like a charm! It also checks if someone has used special characters in the name, address, or city.

5 hours ago, leemahoney3 said:

Just create a PHP file in [YOUR WHMCS ROOT]/includes/hooks (e.g. RestrictClientEmailHosts.php)

Thank you! It started working right out of the box when I placed the PHP file in the hook directory.
 

Edited November 23, 2023 by Looper