MailboxValidator Email Validator


This email validation plugin enables user to reduce invalid sign up by detecting disposable email, free email or role-based email from using your services.

Validating spam, temporary emails and stop visitors signing up with fake email address is important to businesses. To use this email lookup plugin, you don’t have to master the hard part of adding shortcode from scratch, all you need to do is to enable it and you’re ready to go!

You can sign up for a free API key at, that will provide you to validate up to 300 emails every month for free!

Supported Plugins

  • Contact Form 7
  • MailChimp
  • Formidable forms
  • WooCommerce
  • JetPack comments and contact form
  • Profile Builder
  • Ultimate Member registration form
  • Users Ultra registration form
  • Theme My Login
  • WP-Members
  • Paid Membership Pro
  • Form Maker by 10Web
  • Visual Form Builder
  • any WordPress registrations & contact forms
  • and other form or comments plugins that used is_email() function.

Key Features

  • Block invalid email.
  • Block disposable email.
  • Block free email.
  • Block role email.
  • Support domain blacklisting.
  • Enable you to block the users from message sending if failed in validation.

This plugin need a MailboxValidator API key to work. You can get it from MailboxValidator.


  • Setting page for MailboxValidator Email Validator. At here you can add your MailboxValidator API Key and switch on or off the valid, disposable and free email validator.
  • Example of Contact Form 7 email validation.
  • Example of Mailchimp for WordPress email validation.
  • Example of Formidable Forms email validation.
  • Example of Caldera Forms email validation.
  • Example of Contact Form by BestWebSoft email validation.
  • Example of Contact Form Maker email validation.
  • Example of BuddyPress email validation.
  • Example of Profile Builder email validation.
  • Example of WooCommerce registration form email validation.


Installation using WordPress dashboard

  1. Select Plugins -> Add New.
  2. Search for „MailboxValidator Email Validator“.
  3. Click on Install Now to install the plugin.
  4. Click on Activate button to activate the plugin.
  5. Get your MailboxValidator API key before start using the plugin.
  6. Configure the plugin settings, including your API key, domain blacklist and switch on or off the valid, disposable and free email validator.

Manual Installation

  1. Upload the plugin files to the /wp-content/plugins/mailboxvalidatoremail-validator directory.
  2. Activate the plugin through the ‚Plugins‘ screen in WordPress
  3. Get your MailboxValidator API key through here.
  4. Configure the plugin settings, including your API key, domain blacklist and switch on or off the valid, disposable and free email validator.


How can this plugin help to validate form details?

This plugin will validate those email and make sure that it is valid or not belong to disposable, free email or role-based. In other words, it will reject those email which is invalid, disposable or free email, depends on your settings.

What is role-based email address?

A role-based email address is the email address that front part like admin@, sales@, support@ and so on.

Do I need an API key to use this plugin?

Yes. You can sign up for a FREE API key from MailboxValidator to use this plugin.

Unable to find your answer here?

Send us email at


Für dieses Plugin gibt es keine Rezensionen.

Mitwirkende & Entwickler

„MailboxValidator Email Validator“ ist Open-Source-Software. Folgende Menschen haben an diesem Plugin mitgewirkt:




  • Tested with WordPress 5.5.


  • Update FAQ section in readme.


  • Minor improvement for validation process.


  • Display more information about MailboxValidator API plan.


  • Show the remaining credits in the plugin setting page.
  • Add the option to enable/disable the debugging log.


  • Added source parameter to keep track for API calling.


  • Reformat the code to follow the WordPress Coding Standards.
  • Added js files that are missing.
  • Changed descriptions in settings page.


  • Added feedback feature when deactivate the plugin.
  • Reorganize the js files.


  • Added block role-based email address feature.


  • Added domain blacklisting feature.


  • Fixed minor error.


  • Initial Release