A Mail Transport Agent (MTA) is essential for
sending email from a Red Hat Linux system. The Mail User
Agent (MUA) such as Mozilla Mail,
Mutt, Pine, and
Evolution is used to read and compose
email. When a user sends an email from an MUA, the messages is handed off
to the MTA, which sends the message to a series of MTAs until it reaches
its destination.
Even if a user does not plan to send email from the system, some automated
tasks or system programs might use the /bin/mail
command to send email containing log messages to the root user of the
local system.
Red Hat Linux 7.3 provides two MTAs: Sendmail and Postfix. If both are
installed, sendmail is the default
MTA. Red Hat Mail Transport Agent Switcher allows
a user to select either sendmail or
postfix as the default MTA for the system.
To start Red Hat Mail Transport Agent Switcher, use one
of the following methods:
On the GNOME desktop, go to the (on the Panel) =>
=> => .
On the KDE desktop, go to the (on the Panel)
=> .
Type the command redhat-switchmail at a shell
prompt (for example, in an XTerm or GNOME terminal).
The program automatically detect if the X Window System is running. If it
is running, the program starts in graphical mode as shown in Figure 16-1. If X is not detected, it starts in
text-mode. To force Red Hat Mail Transport Agent
Switch to run in text-mode, use the command
redhat-switchmail-nox.
If you selected Postfix, you must make sure the
sendmail service is stopped and the
postfix service is started:
/sbin/service sendmail stop
/sbin/service postfix start |
If you selected Sendmail, you must make sure the
postfix service is stopped and the
sendmail service is started:
/sbin/service postfix stop
/sbin/service sendmail start |
 | Tip |
|---|
| | For more information about email protocols and MTAs, refer to the
Official Red Hat Linux Reference Guide. |
