Sergey Biryukov

Checks via Google Search if the comment being left is a common spam comment.
Inspired by <a href="http://alexking.org/projects/wordpress" rel="nofollow ugc">Delink Comment Author</a> plugin from Alex King.

Unique Comments

Checks via Google Search if the comment being left is a common spam comment.

HivePress

HivePress Messages is an extension for <a href="https://wordpress.org/plugins/hivepress/" rel="ugc">HivePress</a> plugin. It allows users to send private messages.
<a href="https://listinghive.hivepress.io/" rel="nofollow ugc">Demo</a> | <a href="https://help.hivepress.io/" rel="nofollow ugc">Docs</a> | <a href="https://community.hivepress.io/" rel="nofollow ugc">Support</a>

Unique Comments vs HivePress Messages