Distributed electronic mail
Electronic mail (e-mail) on the SCO OpenServer system is handled by
two distinct processes:
On a stand-alone system, the MUA (such as mail)
and MTA (such as sendmail) interact directly.
The MUA, acting on behalf of the sending user, contacts
the MTA, which routes the mail to the local recipient. The
recipient reads the mail by using an MUA.
The Mail User Agent (MUA)
enables users to send, read, and manage mail messages,
and transfers outgoing mail to a Mail Transfer Agent.
The Mail Transfer Agent (MTA) is
the group of programs that route and deliver messages to their
On a networked system, the MTA on the sending system has
the additional task of determining whether the mail should be delivered
to a local user or sent to another machine on the network, and, if
sent to another machine, what communications channel (such as
SMTP, the Simple Mail Transport Protocol) to use.
When the MTA on the
destination system receives the mail message,
that MTA forwards the message to the appropriate user.
SCO OpenServer provides a choice of Mail Transfer Agents:
(Multichannel Memorandum Distribution Facility), the SCO
MTA that is included with the SCO OpenServer
a commonly used alternative MTA that is also included
with the SCO OpenServer operating system
MMDF offers several substantial benefits over sendmail,
For a more detailed comparison of the
differences between MMDF and sendmail, see
``Comparison of sendmail with MMDF''.
For more information on these MTAs, see
``Managing mail with MMDF'',
Configuration files that are easy to read and understand.
The ability for end users to configure their own sorting parameters.
A larger set of supported delivery agents.
Both MTAs can use a variety of
hostname-to-Internet address mapping schemes;
the most effective when connecting to the Internet is the
Domain Name Service (DNS).
Configuring a mail transfer agent
To configure electronic mail, you must complete the following
configuring DNS (Domain Name Service) if desired.
choosing an MTA (Mail Transfer Agent), either at
installation time or after the system is installed.
establishing physical connections and configuring networking drivers.
configuring the MTA.
Administering a mail transfer agent
Administering a mail system includes regularly:
monitoring the log file.
monitoring the mail queue.
Distributed name services
Administering an installation server
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003