You can readily set up a mail service if your site does not provide connections to email services outside your company or if your company is in a single domain.
Mail requires two types of configurations for local mail. Refer to Figure 2–1 in Local Mail Only for a representation of these configurations. Mail requires two more configurations for communication with networks outside your domain. Refer to Figure 1–1 in Overview of the Hardware Components or Figure 2–2 in Local Mail and a Remote Connection for a representation of these configurations. You can combine these configurations on the same system or provide these configurations on separate systems. For example, if your mail host and mail server functions are on the same system, follow the directions in this section for setting up that system as a mail host. Then, follow the directions in this section for setting up the same system as a mail server.