The simplest mail configuration, as shown in Figure 13–1, is two or more workstations that are connected to one mail host. Mail is completely local. All the clients store mail on their local disks, and the clients act as mail servers. Mail addresses are parsed by using the /etc/mail/aliases files.
To set up this kind of mail configuration, you need the following.
The default /etc/mail/sendmail.cf file, which requires no editing, on each mail client system.
A server that is designated as the mail host. If you are running NIS or NIS+, you can make this designation by adding mailhost.domain-name to the /etc/hosts file on the mail host. If you are running another name service, such as DNS or LDAP, you must provide additional information in the /etc/hosts file. See How to Set Up a Mail Host.
If you are using a name service other than NIS or NIS+, you need matching /etc/mail/aliases files on any system that has a local mailbox.
Enough space in /var/mail on each mail client system to hold the mailboxes.
For task information about setting up your mail service, refer to Setting Up Mail Services. If you are looking for a particular procedure that is related to setting up your mail service, refer to Setting Up Mail Services (Task Map).