Comment Notifier lets user to subscribe the comment thread of each single
post of your blog. It improves traffic and loyalty.
Notification emails are fully customizable (both plain text or html) with a number
of "tags" to insert author name, post link and title, receiver name and so on.
The "subscribe me" checkbox in the comment form area can be added automatically or manually.
Read more on
Comment Notifier offical page.
An extended alternative to Comment Notifier plugin is my
Comment Plus
plugin with more notification options and that integrates the features of
Comment Image
plugin.
Other plugins by Stefano Lissa: