This plugin for sent information about comment to post author. 
Information about author name and author e-mails sets in custom fields for each post. 
In configuration of plugin you can set keys name for custom fields. By default this is “Author name” and “Author email”. 
Also can set subject and body of notification e-mail. 
In body of e-mail you can use macros:
[name] – name of authr from custom field 
[url] – post url 
[title] – post title 
[comment] – comment text

Comment Inform

This plugin for sent information about comment to post author. Infromation about authors gets from custom fields. Custom fields keys are "Author  …

Alex King

Crowd Favorite

If you’ve decided to move things around on your site, you might overlook a few redirects and end up with some broken URLs. This will help you catch those so you can take care of them.

404 Notifier

Log 404 (file not found) errors on your site and get them delivered to you via e-mail or RSS.

Comment Inform vs 404 Notifier