28.1 The structure of the Email System
There are a number of components that make up a complete email system. Below is a brief description of each one:
28.1.1 Mail User Agent
This is the part of the system that the typical user is likely to be most familiar with. The Mail User Agent (MUA), or mail client, is the application that is used to write, send and read email messages. Anyone who has written and sent a message on any computer has used a Mail User Agent of one type or another.
Typical Graphical MUA’s on Linux are Evolution, Thunderbird and KMail. For those who prefer a text based mail client, there are also the more traditional pine and mail tools.
28.1.2 Mail Transfer Agent
The Mail Transfer Agent (MTA) is the part of the email system that does much of the work of transferring the email messages from one computer to another (either on the same local network or over the internet to a remote system). Once configured correctly, most users will not have...