You are the Exchange administrator for your company. The Exchange organization contains a single server that runs Exchange Server 2003. Users send many order confirmations and order acknowledgement receipts to customers by using email. Users report that they are not being notified quickly enough when a message to an external customer is not deliverable. You need to ensure that when a message is not delivered within one hour, a notification is sent to the message originator. How should you configure the SMTP virtual server?