An auto-responder is a predefined email, which is sent automatically as an answer to each and every message received in a mailbox with this feature activated. The two most typical examples for employing this function are automatic emails that one is briefly out of the office or that an order has been received successfully. An auto-responder can also be used as a common verification that an email is delivered successfully, which is often something rather important in business communication. The message that's delivered can be more or less anything and could be changed depending on the circumstances and what the auto-responder will be used for. As the feature is activated server-side, there isn’t anything you are required to do manually and you do not need an email application to be enabled constantly for an automatic reply to be mailed to the individual sending you an email.