Comment Mail™ (WP Comment Subscriptions) 
A WordPress plugin enabling email subscriptions for comments.
Comment Mail™ Pro is a commercial plugin available at http://comment-mail.com. The plugin is hosted here on a public Github repository in order to better faciliate community contributions from developers and users alike. If you have a suggestion, a bug report, or a patch for an issue, feel free to submit it here. We do ask, however, that if you are using the plugin on a live site that you please purchase a valid license from the website. We cannot provide support to anyone that does not hold a valid license key.