An auto-responder e-mail is an e-mail that is sent back automatically to everyone who sends an email to an email address with this feature activated. The senders will receive the automatic answer once their messages are received and you'll not need to do anything whatsoever manually. A couple of examples of using auto-responder messages are sending a validation that a transaction is received and also the order is now being prepared or that an individual is on a break and won't be available for a certain time frame. In the first situation the option can be enabled permanently, while in the second one it's non permanent. Even if you work with an email address only for private correspondence, you may use an auto-responder to let the original sender know that their e-mail has been received successfully.