The sendmail program is a mail transport agent. The program uses a configuration file to provide aliasing and forwarding, automatic routing to network gateways, and flexible configuration. The Oracle Solaris OS supplies standard configuration files that most sites can use. Chapter 1, About Mail Services provides an introduction to the components of mail services and a description of a typical mail service configuration. Chapter 2, Administering Mail Services explains how to set up and administer an electronic mail system. This chapter provides information about the following topics.