thebluecube

This plugin adds some additional features to the Gravity Forms plugin:
<ul>
<li>Input ID change (if the form has not received any entries yet)</li>
<li>Advanced input validations</li>
<li>Form access control</li>
<li>Advanced conditional logic shortcode to be used in email notifications</li>
</ul>
Documentation: https://thebluecube.com/wordpress-plugins/bluecube-mighty-gravity-forms/documentation/

Blue Cube Mighty Gravity Forms

This plugin adds some additional features to the Gravity Forms plugin:

MailboxValidator

This email verification plugin enables Contact Form 7 users to validate email address before sending the form. It uses MailboxValidator email validation service to check if an email address is disposable email address or free email address in order to block invalid email from signing up. You can <a href="https://www.mailboxvalidator.com/plans#api" title="MailboxValidator API key sign up" rel="nofollow ugc">sign up for a free API key</a> at mailboxvalidator.com with 300 FREE email validation credits every month!
Note: Contact Form 7 must be installed and activated before using this MailboxValidator email validation plugin.
Key Features
<ul>
<li>Accurate email verification result.</li>
<li>Support invalid email validation.</li>
<li>Support disposable email validation.</li>
<li>Support free email validation.</li>
<li>Support role-based email validation.</li>
<li>Support domain blacklisting.</li>
<li>Support trusted domain whitelisting.</li>
<li>Enable you to block the users from message sending if failed in validation.</li>
</ul>
This plugin need a MailboxValidator API key to work. You can get it from <a href="https://www.mailboxvalidator.com/plans#api" title="MailboxValidator API key sign up" rel="nofollow ugc">here</a>.

Email Validator for Contact Form 7

Email validation for Contact Form 7. Reduce registration spam with invalid email, block disposable and block free email.

Blue Cube Mighty Gravity Forms vs Email Validator for Contact Form 7