Introduction to the Components of Mail Services
Many software and hardware components are required to establish a mail service. The following
sections give a quick introduction to these components. These sections also provide some of the
terms that are used to describe the components.
The first section, Overview of the Software Components, defines the terms that are used when discussing the software
parts of the mail delivery system. The next section, Overview of the Hardware Components, focuses on the functions
of the hardware systems in a mail configuration.
Overview of the Software Components
The following table introduces some of the software components of a mail system. Refer
to Software Components for a complete description of all of the software components.
Component |
Description |
|---|
.forward files |
Files that
you can set up in a user's home directory to redirect mail or to
send mail to a program automatically |
mailbox |
A file on a mail server that is the
final destination for email messages |
mail addresses |
Address that contains the name of the recipient and
the system to which a mail message is delivered |
mail aliases |
An alternate name that
is used in a mail address |
mail queue |
A collection of mail messages that needs to
be processed by the mail server |
postmaster |
A special mail alias that is used to report
problems and to ask questions about the mail service |
sendmail configuration file |
A file that
contains all the information necessary for mail routing |
Overview of the Hardware Components
A mail configuration requires three elements, which you can combine on the same system
or provide in separate systems.
A mail host – A system that is configured to handle email addresses that are difficult to resolve
A minimum of one mail server – A system that is configured to hold one or more mailboxes
Mail clients – Systems that access mail from a mail server
If users are to communicate with networks outside your domain, you must also add
a fourth element, a mail gateway.
Figure 12-1 shows a typical electronic mail configuration, using the three basic mail elements plus a
mail gateway.
Figure 12-1 Typical Electronic Mail Configuration
Each element is described in detail in Hardware Components.
