Today, electronic messaging is part of the communication backbone, the core of information dissemination within companies of all sizes. Everyone uses e-mail, from the mailroom to the laboratories to the CEO's office. And if you're in charge of an organization's mail server, you'll be notified (incessantly) when it stops working.
This chapter explains how to set up a mail server in Red Hat Linux to send and receive messages. In particular, it focuses on configuring a Sendmail mail server, but also tells how you might transition to a Postfix mail server (which is also in the Red Hat Linux distribution).
Although the primary aspects of mail server configuration are discussed in this chapter, many configuration aspects are beyond its scope and thus are not addressed. Because security is an important concern when you're connected to the Internet, it is given considerable focus here.
Mailing list configuration and administration are also discussed in this chapter, detailing how mailing list management software integrates and interfaces with the mail server.