Mark Jaquith

Comment management in WordPress isn’t too hard when you manually approve each comment. You know which comments you’ve seen, and which you haven’t. The only downside is that you have to approve the comments before they appear. Comment Inbox gives you the ease of the moderation queue with the freedom of unmoderated comments. It’s a better way to deal with spam and bacn on your blog.
Here’s how it works:
<ul>
<li>All comments except caught spam go into moderation (renamed “Comment Inbox”)</li>
<li>All comments in your Comment Inbox immediately show up on the blog — so conversations don’t wait on your moderation skills</li>
<li>There are three actions that can be performed on comments in your Comment Inbox: Archive (i.e. mark as read), Spam, Delete</li>
<li>When your Comment Inbox is empty, you can rest easy knowing you’ve dealt with all your new comments</li>
</ul>
For the history of this plugin, please see <a href="http://markjaquith.wordpress.com/2008/03/20/the-comment-inbox/" rel="nofollow ugc">The Comment Inbox</a>.

Comment Inbox

Enables a "Comment Inbox" that gives you the power of a moderation queue without having to manually approve every comment.

Yakup Hoca

The visitors send their questions in comments, then they leaves our web sites. When we reply their comment to answer their questions, this plugin sends an e-mail about this. So that, the visitor will learn this situation and return to our site to read our answer.
For support: <a href="http://www.yakuphoca.com/comment-reply-by-admins-notifier-plugin/" title="Support by Yakup Hoca" rel="nofollow ugc">Plugin URI</a>

Comment Reply by Admins Notifier

This plugin sends an e-mail notify when an admin or an editor of site reply a comment.

Comment Inbox vs Comment Reply by Admins Notifier