An auto-responder is a predefined e-mail, which is sent automatically as an answer to each and every email received inside a mailbox with this feature activated. The two most common instances for employing this function are automatic e-mails that one is temporarily away from the office or that an order has been received successfully. An auto-responder could also be used as a standard verification that an e-mail is received successfully, which may be something very important in enterprise e-mail correspondence. The message which is delivered can be more or less anything and could be changed with respect to the circumstances and exactly what the auto-responder will be used for. As the feature is activated server-side, there isn’t anything you are expected to do by hand and you don't need an e-mail application to be enabled constantly for the automatic reply to be delivered to the individual sending you an email.