shawfactor

mattsenate

This plugin is can be used for petitions, events, or any verified list and as far as I know is unique in WordPress.
Creating a petition/list/signup is as easy as adding a shortcode to a post or page (or CPT). From there additional editors are available to configure easch aspect of the sign up. Everything is completely self hosted and all list members become users of your site (not a third parties).
Available shortcodes:
[lh_signing_form] (enable signatories on any post, page, or custom post type)
Unconfirmed signatories: [lh_signing_unconfirmed_count]
Confirmed signatories: [lh_signing_confirmed_count]
Total signatories: [lh_signing_total_count]
[lh_signing_unconfirmed_list] (unformated list)
[lh_signing_confirmed_list] (unformated list)
You can customise the display of the signing form ([lh_signing_form]) via a number of shortcode arguments more information is available <a href="https://lhero.org/portfolio/lh-signing/" title="Additional Plugin documentation" rel="nofollow ugc">here</a>

LH Signing

LH Signing allows you to create configurable validated lists like petitions or event sign ups. It is the only self hosted solution in WP

Antideo

The email validator is designed by Antideo to help combat spam coming in through contact forms. Antideo <a href="https://www.antideo.com/email-validation/" rel="nofollow ugc">validates email addresses</a> entered through your contact forms in real time to prevent inquiries from fake email addresses. The email validator plugin comes packed with several features that help you –
<ul>
<li>Check the syntax of the email entered, to quickly flag the error to the visitor</li>
<li>Check for disposable or temporary emails</li>
<li>Prevent inquiries from free ESP’s like Gmail, Yahoo, etc (Can be switched on and off)</li>
<li>Prevent inquiries from role-based emails like info@, support@, admin@ etc (Can be switched on and off)</li>
<li>Check MX records to identify invalid emails</li>
<li>Create and maintain your own local whitelist of domains and emails </li>
<li>Create and maintain your own local blacklist of domains and emails</li>
</ul>
Armed with the capabilities of our plugin you would be able to eliminate a major portion of contact form spam, as spammers seldom use a valid business email address. Our plugin out of the box is compatible with major forms like
<ul>
<li>Contact Form 7</li>
<li>Gravity Forms</li>
<li>Mailster Form</li>
<li>WooCommerce</li>
<li>MailChimp</li>
<li>Ninja Forms</li>
<li>Formidable forms</li>
<li>JetPack comments and a contact form</li>
<li>MailPoet</li>
<li>WP-Members</li>
<li>Paid Membership Pro</li>
<li>Form Maker by 10Web</li>
<li>Visual Form Builder 
And pretty much any other form that uses the default WordPress is_email() function. The plugin is very easy to install and activate, no tech knowledge whatsoever is needed to get going with the plugin.</li>
</ul>
Advantages of our plugin
<ul>
<li>No limits on the number of validations – go crazy, it’s unlimited!!</li>
<li>Real time validations done in a fraction of a second</li>
<li>Extensive database of 84K+ disposable email domains and constantly being updated with newer ones</li>
<li>Clean and super friendly UI that is easy to use</li>
<li>A powerful free version and an affordable premium version </li>
</ul>
We are literally eating our own dog food, implementing the <a href="https://www.antideo.com/wordpress-email-validation-plugin/" rel="nofollow ugc">Antideo Email Validation plugin</a> on several websites that we own, which has resulted in spam inquiries going down by over 87%.
You can access more information on the plugin as well as the several aspects of email validation <a href="https://www.antideo.com/blog/" rel="nofollow ugc">here</a>.
Disclaimer: This plugin is an email validator and not an email verifier

Antideo Email Validator

Form email validation, Email Blacklist, Domain Blacklist, Form email check, Real time email validator Requires at least: 4.7 Tested up to: 6.5.

LH Signing vs Antideo Email Validator