Make a list of mail address forms that your organization (feel free to make up an organization for this) and write a set of rules for parsing them.
POP3 separates message retrieval and deletion by allowing a user to retrieve and view a message without deleting it from the permanent mailbox. What are the advantages and disadvantages of such separation?
How does the TOP command operate and why is it useful?
How can a UNIX sendmail program be used to implement a mail gateway?
Many sites that use a bastion host arrange for software to scan all incoming files before admitting them to the organization. Why do organizations scan files?
Read the description of a packet filter for a commercially available router. What features does it offer?
Most users are not aware that SMTP transfers messages in ASCII, and that anyone watching network traffic can see the contents of an email message. How could you secure sensitive information when transmitting via SMTP so ASCII contents are not revealed?
Can a firewall be combined with a NAT? What are the consequences?
