Akismet checks your comments against the Akismet Web service to see if they look like spam or not.
Spam protection, all-in-one, premium anti-spam plug-in. No comments spam, registrations & users spam, no contact form spam, protects any forms.
Send comment moderation notifications ONLY to the Author, not to the site Administration address any more.
Integrate Facebook Comments, Google Plus Comments and/or Disqus Comments on your website
WordPress plugin to fight with 450+ referrer spammers (like semalt, buttons-for-website and many more).
Comment moderation is a drag. Have your users lend a hand by flagging offensive comments and scrubbing your site clean.
Add the parent comment to comments in the WP Admin area, in order to assist with comment moderation
Hide comments of a specific post and show a predefined text instead.
Hide unwanted comments without deleting them. Readers can click on the "Show" link to read the buried comment.
One click comment approval for WordPress from your Gmail account.
This plugin will stop comments spam entirely, for free. It requires all users to connect their verified RubyID account before they can post a comment.