comment email responder

Hello,

I’m looking for a plugin or comment management system that will email the original commentor when I respond to his/her comment from my back-end comment management system. Looks like DISQUS may do this, but not sure I want to go that way as it forces the user to go through an extra step to simply comment on a post.

Does anyone know of a comment email responder that works with 2.8 and above? Seems like this would drive traffic and encourage discussion.