higherfield

Kaigai Spam Mail Blocker is a WordPress plugin that automatically detects and blocks spam or abusive contact form submissions, especially those originating from overseas.
The plugin analyzes submitted content and blocks messages that do not contain Japanese characters or consist primarily of alphanumeric characters, which are common patterns in spam messages.
Supported form plugins:
<ul>
<li>Contact Form 7</li>
<li>Elementor Pro Forms</li>
</ul>
No configuration is required. Simply install and activate the plugin.

Kaigai Spam Mail Blocker

Blocks spam submissions from overseas contact forms. Supports Contact Form 7 and Elementor Pro Forms.

Sajjad Hossain Sagor

Using This Plugin You Can Block Spammy Disposable & Temporary Email Domains From Submit On GravityForms form. Filtering Spammy Emails Will Keep Your Subscriber List Spam Free.
<h4>Features:</h4>
<ul>
<li>Designed As Plug & Play So That Anyone Can Use</li>
<li>Toggle Feature To Enable/Disable Blocking on Individual Form</li>
<li>Easily Change Disposable/Temporary Emails Found Error Message (Default Message Provided)</li>
</ul>
Are You Getting Too Much Spammy Disposable or Temporary Emails Submission On Your GravityForms form which are not much valuable? You can use this plugin to block/prevent disposable emails like 10MinuteMail and GuerrillaMail from submission on any GravityForms form.
Credits 
– https://github.com/andreis/disposable

Disposable Email Blocker – GravityForms

Prevent From Submitting Any Disposable/Temporary Emails On GravityForms Forms.

Kaigai Spam Mail Blocker vs Disposable Email Blocker – GravityForms