r-a-y

User registration spam is prevalent in BuddyPress.
One way to dramatically decrease signup spam is to restrict the email address domains that users can sign up with.
WordPress multisite has a native option called “Limited Email Registrations”. But this option requires you to enter the full email domain. For example, if you only wanted to allow .edu email addresses to register, this is not possible.
This plugin restricts registrations to the email domains that you are not specified in the blacklist and works in WordPress single-site and multi-site.
Plugin is a fork of r-a-y’s BP Restrict Signup by Email Domain.
Tested on BuddyPress 2.5, but should work all the way down to BuddyPress 1.6.

BP Blacklist Signup by Email Domain

Only allow users with email addresses not on the domain blacklist to register in BuddyPress.

DeveloperWil

If you need to prevent email addresses or entire email domains from being sent on an Elementor Form, this plugin will do that.
Stop unwanted Elementor Forms spam and create an email or domain name block list for your forms.
This is for Elementor Pro users only. This will not work with the free version of Elementor as it doesn’t support forms.
<h4>Plugin Page</h4>
<a href="https://zeropointdevelopment.com/wordpress-plugins/email-blacklist-for-elementor-forms/" title="Email Blacklist For Elementor Forms WordPress Plugin" rel="nofollow ugc">Email Blacklist For Elementor Forms</a>

Email Blacklist For Elementor Forms

Adds a text area control called "Blacklist" to the Elementor Forms control. Blocks outgoing emails if they match with any on the blacklist.

BP Blacklist Signup by Email Domain vs Email Blacklist For Elementor Forms