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

Configuring a System
Setting Up Mail Services
Chapter 3276
✓ Each computer needs to run its own copy of the
sendmail daemon to “listen” for incoming mail.
Selecting a Topography
The topography you use depends on your needs. Here are some things to
consider when choosing your electronic mail network topography:
Security By using a topography with a hub computer you can
better protect work that is being done on machines
within your workgroup or organization. The single
point of entry to your internal network (a gateway
computer) is a lot easier to defend against
unauthorized entry.
Data Centralization
By having your mail files on a single machine or
directory structure, it is easier to back up your data.
Company Appearance and Future Planning
By using one of the topographies that use a hub
computer, a small company can look more like a large
corporation. As the company grows, the centralized
mail processing can be easily moved to the jurisdiction
of a corporate communications group.
Traffic Levels If e-mail traffic levels are expected to be high, you
might not want to use a single hub for processing all
electronic mail.
MIME Applications
Gone are the days when electronic mail messages contained only ASCII
text. Today people want to send other types of data: audio clips, still
graphics (in a variety of formats), video clips, etc.
Because Mail Delivery Agents were developed to handle the 7-bit ASCII
data in text-only messages and not the 8-bit binary data contained in
audio, graphics, and video, a method is needed for encoding the binary
data to be transported by the text-only transport agents. The system
developed for encoding the binary data is known as MIME (for
Multipurpose Internet Mail Extensions).
Most modern Mail User Agents (including the CDE mail client, dtmail)
can process MIME-encoded e-mail messages. For complete details about
how MIME works, see RFC 1521. See also: elm (1).