jamiechong

A lot of registration spam comes from emails with a subdomain. Spammers control a domain such as buymyjunk.com and then attempt to register on your site with emails such as irenemwd@foster2.buymyjunk.com and jakemgm@foster7.buymyjunk.com. This plugin simply blocks all registrations using a subdomain.
Reputable users will have a normal email address from a reasonable domain like @gmail.com, @mylegitbusiness.com, @outlook.com, @myschool.edu, etc.
There is no configuration and no setup. It simply just works. The plugin logs all blocked registrations so you can find potential false-positives. Find a link to this log file on the Plugins page where you activate/deactivate this plugin.

Ban Subdomain Emails

Prevent people from registering with emails that contain a subdomain to help reduce spam.

<ul>
<li>When judging that Akismet is SPAM when the comment is processed</li>
<li>When marking it as SPAM in the comment section of the dashboard</li>
<li>When you make the approval status SPAM when the comment section of the dashboard edits the comment</li>
</ul>
List IP address from the database in case of the above-mentioned, and Deny the IP address. .htaccess is updates.
It changes in the comment block from
BEGIN written by WordPress plugin – Akismet htaccess writer
to
END written by WordPress plugin – Akismet htaccess writer
in the content of the .htaccess file.
After the .htaccess file, it is written in the tail when the block identifier is not found.
***** Please do not do the contact to the author of the Akismet plug-in for this plug-in *****

Akismet htaccess writer

in connection with Akismet, write in a .htaccess file

Ban Subdomain Emails vs Akismet htaccess writer