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.

Sergey Biryukov

Adds parent comment ID meta box to a comment editing page. Use to make existing comments threaded.

Edit Parent Comment ID

Instead, I advise you to use this plugin Change Comment Parent



New alternative to this plug-in

Adds parent comment ID meta box to a comment editing page.

Comment Inbox vs Edit Parent Comment ID