The Comment Email Responder plugin is one of those plugins that make you wonder why no one else ever thought of it. This handy plugin makes it easy for a WordPress administrator to respond to a comment and simultaneously send an email to the commenter. If the commenter has subscribed to receive notification of any new comments, the email is not sent. Brilliant! I’ve often found myself responding to a commenter, and then searching through my comments in the admin for their email address so I can send them an email saying that I’ve responded. This plugin pares the process down to one simple step.