I recently ran across a Wordpress plugin called CommentRelish by Justin Shattuck and thought this would be a great extension for BlogEngine.Net.  On Justin's site he explains this extension best:

Visitors love interaction, especially a personable approach at gaining their attention and spiking their interests. Increasing the overall readership of your blog revolves primarily around content, accessibility and presentation. In an attempt to gain return readers and possibly subscribers, I present Comment Relish.  Comment relish is a Wordpress plugin BlogEngine.Net extension developed to send an e-mail message to users who comment on your website who have never commented before. 

So I set out to create an extension that does the same thing as Justin's plug-in.  I decided that I would credit his work by using the same name and including his information in the source code.  To install this extension you just need to copy the two files, CommentRelish.cs and CommentRelishHistory.cs into ~/app_code/extensions folder.  I have pre-configured the extension with an email subject and body but feel free to customize it to your liking.

It's important to note that an email will only be sent out to the same email address one time.  The history of email messages sent is stored in the CommentRelishHistory extension and can be managed using the ExtensionManager pages.  So give this extension a try and let me know if you run into any issues.

CommentRelish.zip (2.93 kb)

UPDATED May 18th, 2009: After receiving some feedback of a null exception error I updated the code and removed this issue. The download link contains the latest version (v1.1) for those interested in obtaining the corrected code.