Red Hat ENTERPRISE LINUX 5 - VIRTUAL SERVER ADMINISTRATION, Руководство по развертыванию

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Fetchmail
387
• Uncomment the
mydestination = $myhostname, localhost.$mydomain
line.
• Uncomment the
mynetworks
line, and replace
168.100.189.0/28
with a valid network setting
for hosts that can connect to the server.
• Uncomment the
inet_interfaces = all
line.
• Comment the
inet_interfaces = localhost
line.
• Restart the
postfix
service.
Once these steps are complete, the host accepts outside emails for delivery.
Postfix has a large assortment of configuration options. One of the best ways to learn how to configure
Postfix is to read the comments within
/etc/postfix/main.cf
. Additional resources including
information about LDAP and SpamAssassin integration are available online at
http://www.postfix.org/
.
24.3.3. Fetchmail
Fetchmail is an MTA which retrieves email from remote servers and delivers it to the local MTA. Many
users appreciate the ability to separate the process of downloading their messages located on a
remote server from the process of reading and organizing their email in an MUA. Designed with the
needs of dial-up users in mind, Fetchmail connects and quickly downloads all of the email messages
to the mail spool file using any number of protocols, including POP3 and IMAP. It can even forward
email messages to an SMTP server, if necessary.
Fetchmail is configured for each user through the use of a
.fetchmailrc
file in the user's home
directory.
Using preferences in the
.fetchmailrc
file, Fetchmail checks for email on a remote server and
downloads it. It then delivers it to port 25 on the local machine, using the local MTA to place the email
in the correct user's spool file. If Procmail is available, it is launched to filter the email and place it in a
mailbox so that it can be read by an MUA.
24.3.3.1. Fetchmail Configuration Options
Although it is possible to pass all necessary options on the command line to check for email on a
remote server when executing Fetchmail, using a
.fetchmailrc
file is much easier. Place any
desired configuration options in the
.fetchmailrc
file for those options to be used each time
the
fetchmail
command is issued. It is possible to override these at the time Fetchmail is run by
specifying that option on the command line.
A user's
.fetchmailrc
file contains three classes of configuration options:
•
global options
— Gives Fetchmail instructions that control the operation of the program or provide
settings for every connection that checks for email.
•
server options
— Specifies necessary information about the server being polled, such as the
hostname, as well as preferences for specific email servers, such as the port to check or number of
seconds to wait before timing out. These options affect every user using that server.
•
user options
— Contains information, such as username and password, necessary to authenticate
and check for email using a specified email server.