An auto-responder is usually a predefined email message, which can be sent automatically as an answer to each and every message received inside a mailbox with this function enabled. The two most common instances for using this feature are automated email messages that one is temporarily out of the office or that an order is received successfully. An auto-responder could also be used as a basic verification that an e-mail has been received successfully, which is often something quite important in enterprise e-mail correspondence. The message that is delivered can contain pretty much anything and could be changed depending on the circumstances and exactly what the auto-responder will be employed for. As the option is enabled server-side, there isn’t anything you are required to do by hand and you do not need an e-mail application to be active constantly for the automatic reply to be sent to the individual sending you an email.