By default, in a multi-authors blog, you can get WordPress to notify the post author when a new comment is posted. To do this, you just have to update the “Email me whenever” field in “Settings -> Discussion”.

Now if you are using Disqus as your comment system, you will find that it won’t notify the author when a new comment is posted. Instead, it will only notify the moderators.

To fix this, go to the Disqus-Comment-System folder in the Plugins directory. Open the disqus.php in a text editor. Scroll down to line 289 where you see the following:

$comment_id = $commentdata['comment_ID'];
update_comment_meta($comment_id, 'dsq_parent_post_id', $comment->parent_post);
update_comment_meta($comment_id, 'dsq_post_id', $comment->id);

Add in the line “wp_notify_postauthor($comment_id);” so that it becomes:

$comment_id = $commentdata['comment_ID'];
update_comment_meta($comment_id, 'dsq_parent_post_id', $comment->parent_post);
update_comment_meta($comment_id, 'dsq_post_id', $comment->id);
wp_notify_postauthor($comment_id);

Save, upload and replace the file back to the server.

That’s it. It should notify your authors whenever there is a new comment.