Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual page 412

Chapter 24. Email
Important
Before using Postfix, the default MTA must be switched from Sendmail to Postfix.
24.3.2.1. The Default Postfix Installation
The Postfix executable is /usr/sbin/postfix. This daemon launches all related processes needed
to handle mail delivery.
Postfix stores its configuration files in the /etc/postfix/ directory. The following is a list of the more
commonly used files:
• access — Used for access control, this file specifies which hosts are allowed to connect to Postfix.
• aliases — A configurable list required by the mail protocol.
• main.cf — The global Postfix configuration file. The majority of configuration options are specified
in this file.
• master.cf — Specifies how Postfix interacts with various processes to accomplish mail delivery.
• transport — Maps email addresses to relay hosts.
Important
The default /etc/postfix/main.cf file does not allow Postfix to accept network
connections from a host other than the local computer. For instructions on configuring
Postfix as a server for other clients, refer to
Configuration".
When changing some options within files in the /etc/postfix/ directory, it may be necessary to
restart the postfix service for the changes to take effect. The easiest way to do this is to type the
following command:
/sbin/service postfix restart
24.3.2.2. Basic Postfix Configuration
By default, Postfix does not accept network connections from any host other than the local host.
Perform the following steps as root to enable mail delivery for other hosts on the network:
• Edit the /etc/postfix/main.cf file with a text editor, such as vi.
• Uncomment the mydomain line by removing the hash mark (#), and replace domain.tld with the
domain the mail server is servicing, such as example.com.
• Uncomment the myorigin = $mydomain line.
• Uncomment the myhostname line, and replace host.domain.tld with the hostname for the
machine.
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Section 24.3.2.2, "Basic Postfix