In most modern organizations, e-mail has become the backbone of communications. If you have any doubt, just visit any organization where the mail server has gone down. All productive work grinds to a halt.
Because e-mail has become such an integral component of most networks, you need to know how to manage a mail server. In addition, many Linux services, such as cron, rely on a local mail server to send messages to local users. Accordingly, you need to be familiar with managing a Mail Transfer Agent (MTA) on Linux systems for your Linux+/LPIC-1 exam. In this part of this chapter, we’ll look at the following topics:
• How e-mail works
• Using MTA management commands on Linux
Let’s begin by discussing how e-mail works.