Rating: 4 stars

You have a problem with NF form validation. It detects html fields that contains emails (eg mailto links) as email fields and validates those.

if (!empty($value) && is_string($value) && preg_match('/@.+\./', $value) && !str_contains($value, "\n") && !str_contains($value, '\n')) {
// rest of the code
}

Your approach needs to be changed to:

if (!empty($value) && is_string($value) && preg_match('/@.+\./', $value) && !preg_match('/mailto:/i', $value)) {
  $ninjaForm = new Zerobounce_Email_Validator_Form_Public('ninjaforms', $form_data['id']); 
  // rest of the code
}

This should be safer to validate only email addresses (or use a better regex).

Rating: 4 stars

Been using this a while and it works pretty well; very useful for rejecting fake email addresses used by spammers/scammers, and also for validating real users/customer email addresses (where they sometimes mis-type their email address).

So, why only 4 stars?

Well simply because I asked about personal (local) whitelisting and blacklisting functionality when I spoke to their onboarding rep., and was promised it would be added soon; over 7 months later, still no sign of this.

As a paying customer, I would like the developers to be more responsive and deliver features/functionality that your rep. promised…

Rating: 5 stars

I have tried so many plugins, honeypot, captchas, IP blocking countries, user agents, etc. but this plugin is great! I was very skeptical at first but after several weeks of using this, we are now on a middle-tier paid plan. We use GravityForms so the plugin was VERY easy to configure and install. Super simple, bravo plugin devs!

Rating: 5 stars

Exactly what I needed for my contact form 7. So simple to integrate with my contact form plugin.

Rating: 5 stars

I have tested this plugin on several of my personal and business websites, it’s awesome. No more spam and fake signups. Service pricing is also decent. Recommended.