This 3 sentence summary provides the key details about configuring a mail server on Cisco Packet Tracer: The document outlines the steps to configure a mail server on Cisco Packet Tracer by connecting 4 PCs, a mail server, and a DNS server to a switch without VLANs or layer 3 devices. It describes assigning IP addresses to each device on the same subnet and then configuring the mail server by setting a domain name, enabling SMTP and POP3 services, and creating usernames and passwords. The DNS server is also configured to convert IP addresses to email addresses for the network.