HP-UX System Administrator's Guide: Configuration Management

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, and so on.
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 and the
X-Window-enabled elm) can process MIME-encoded e-mail messages. For complete
details about how MIME works, see RFC 1521. See also elm(1).
Configuring a System to Send Electronic Mail
To configure an HP-UX system to send e-mail, you need to do two things:
1. Be sure that the executable file for the Sendmail program, /usr/sbin/sendmail,
is on your system.
2. If you are using a Gateway Mail Hub topography, you need to enable site hiding
for each of the client computers in your workgroup, as described in “Using Site
Hiding” (page 125).
Using Site Hiding
With site hiding, the e-mail from users on client computers in your workgroup will
appear to the outside world as if it were sent from the hub computer. Replies to such
mail will be sent to the hub computer (unless a Reply-To: header in the e-mail directs
otherwise).
Configuring a System to Send Electronic Mail 125