http://www.autoresponderpro.net/facebook-autoresponder/
How Do i get an autoresponder for email?
How do i get an auto responder for my email so that i don’t have to answer them? And how do i group my messages, for example i want my facebook messages to appear in a certain group folder.
but unfortunately yahoo does not have autoresponder
How to Add an Auto-Responder Opt-In Box to a Facebook Fan Page