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.

bannersky

*** This plugin has been integrated into the plugin of: <a href="https://wordpress.org/plugins/bsk-gravityforms-blacklist/" rel="ugc">BSK Forms Blacklist</a>
*** Just install the plugin of BSK Forms Blacklist, you data and settings in this plugin will be transfered automatically.
The plugin help you avoid spam submissions from Contact Form 7. You may set it to use blacklist, whitelist, ip address or email to validate visitor’s input and only allow valid entry submitted. It support validate multiple fields.
It is easy to use. You may create your blacklist, whitelist, or email database first, then apply them to one or multiple fields of your form.
It also supports preventing submitting or disable notifications ( skip mails ).
When add email address it support domain name such as *@hotmail.com.

BSK Contact Form 7 Blacklist

*** This plugin has been integrated into the plugin of: BSK Forms Blacklist

BP Blacklist Signup by Email Domain vs BSK Contact Form 7 Blacklist