The simplest mail configuration, shown in Figure 34-1, is one mail host with two or more workstations connected to it. Mail is completely local. All the clients store mail on their local disks and act as mail servers. Mail addresses are parsed using the /etc/mail/aliases files.
To set up this kind of mail configuration, you need:
The default /etc/mail/sendmail.cf file on each mail client system (no editing required)
A server designated as the mail host (add mailhost.domainname to the /etc/hosts file on the mail host; then if you are not running NIS or NIS+, add the mail host IP address line to the /etc/hosts file of all mail clients)
Matching /etc/mail/aliases files on any system that has a local mailbox (unless you are running NIS or NIS+)
Enough space in /var/mail on each mail client system to hold the mailboxes