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

Configuring a System
Setting Up Mail Services
Chapter 3272
• Schedule MIME Applications (if necessary) to allow the user to
experience non-textual information attached to incoming electronic
mail, for example viewing graphics files or video clips, or listening to
audio data.
Mail Delivery Agents
Mail Delivery Agents form the core of the electronic mail system. These
programs, usually running in the background, are responsible for
routing, and delivering electronic mail. On HP-UX and other UNIX
systems, the primary Mail Delivery Agent is sendmail.
Although sendmail can be run directly from a shell command line to
send a message, it is not usually used in this way. Mail User Agents are
usually used as front ends to sendmail for sending mail.
Mail Delivery Agents:
• Deliver mail to local users (users receiving e-mail on the computer
that the Mail Delivery Agent is running on) by scheduling the
/bin/mail program or by forwarding the mail to users on local client
machines.
• Forward e-mail via the appropriate transport mechanism not
intended for local users to other computers/networks for delivery. For
example, UUCP mail would be sent on its way by scheduling (and
passing the message to) the uux program.
• Modify the format of the address information in message headers to
accommodate the needs of the next computer/network in a message’s
delivery path, and to accommodate the delivery method that is being
used to route the message. For example:
UUCP addresses are of the form:
[e-mail]!username
whereas TCP/IP addresses can take one of several forms, for
example:
user
user@computer
[e-mail]