Subscribe to Comments的作者是Mark Jaquith,目前有60,000+个有效安装。已经Tested with 4.3.23版本的wordpress。
Subscribe to Comments is a robust plugin that enables commenters to sign up for e-mail notification of subsequent entries. The plugin includes a full-featured subscription manager that your commenters can use to unsubscribe to certain posts, block all notifications, or even change their notification e-mail address!