Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Setting Up Mail Services
Chapter 3 271
Setting Up Mail Services
Whether you are administering a single system, or a workgroup
containing many systems, you will probably want your users to be able to
communicate with each other using electronic mail (e-mail). This topic
area will help you understand what is involved in setting up e-mail
services for your workgroup.
Components of an Electronic Mail System
To properly configure an electronic mail system you need to know about
the following components:
• “Mail User Agents” on page 271
• “Mail Delivery Agents” on page 272
• “Mail Alias Files” on page 273
• “The Mail Queue” on page 273
• “Networking Topographies” on page 273
• “MIME Applications” on page 276
Mail User Agents
Mail User Agents are the programs that users run to send, and read
e-mail. Mail User Agents that are shipped with HP-UX include mail,
mailx, and elm. There are also commercially available Mail User Agents.
Although Mail User Agents appear to do all the work of transmitting and
receiving e-mail, they are merely the visible part of the entire electronic
mail system. Mail User Agents do not actually deliver the e-mail.
Electronic mail delivery is handled by Mail Delivery Agents.
Mail User Agents:
• Format outgoing messages with proper header information and if
necessary encode the outgoing messages for use by Mail Delivery
Agents in routing the messages.
• Allow users to read, save, and delete incoming electronic mail
messages.