RedHatPostfix Chinese FAQ

Article Title: RedHatPostfix Chinese FAQ. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
After reading some postfix items over the past few days, I 've sorted out some of the problems I 've seen. This article will be updated constantly to add new solutions.
　　
1. Q: Where can I get the postfix RPM installation package?
　　
A: http://www.pobox.com /~ Sjmudd/postfix
　　
2. Q: I downloaded the RPM installation package, but an error occurred during the installation process. Why can't I continue the installation?
　　
A: Postfix is used to replace sendmail. Unless you install it with the source code, sendmail and postfix cannot exist on the same system at the same time. To solve this problem, you must delete sendmail, but before deleting it, you 'd better back up sendmail. Log On As root:
Mkdir/root/sendmail-old
Cp/etc/aliases/root/sendmail-old
Cp/etc/sendmail. cf/root/sendmail-old
Cp/etc/sendmail. cw/root/sendmail-old
Cp/etc/mail/*/root/sendmail-old
Rpm-e sendmail-doc sendmail-cf -- nodeps
(Some errors may occur when you uninstall sendmail. You can use -- nodeps to disable the display of error messages)
Killall sendmail
Rpm-Uvh postfix-postfix-1.1.11-5.i386.rpm
　　
3: Q: I am using Red Hat Linux.
　　
For Versions later than 7.3, sendmail and postfix have been installed, but the system now uses sendmail. What should I do? A: In Red Hat Linux 7.3 and later versions, two MTA software are provided: sendmail and postfix. By default, sendmail is used. If you want to use postfix, you can choose Main Menu Button (the big Button in the lower left corner) => Programs => System => Red Hat Mail Transport Agent Switcher on the gnome gui. KDE Select Main Menu Button (the big Button in the lower left corner) System => Red Hat Mail Transport Agent Switcher. You can also enter the command redhat-switchmail in the terminal. If the Xwindow system is not enabled, the program will automatically start the Xwindow system, you can use redhat-switchmail-nox to force the program to run in text mode. In this program, you can select the MTA software you want to use, whether it is sendmail or postfix. If you want to use postfix, select postfix and save and exit.
/Sbin/service sendmail stop sendmail service
/Sbin/service postfix start the postfix service
　　
In this way, the system's MTA is changed to postfix.
　　
4. Q: How can I configure the installation?
　　
A: The postfix configuration file is located in the/etc/postfix directory. There are four basic configuration files: install. cf main. cf master. cf postfix-script. Mail. cf: The main configuration file of postfix.
Install. cf: contains the postfix initialization settings generated by the installation program during RPM package installation.
Master. cf: the configuration file of the postfix master process. Each row in this file is used
Configure the running mode of the postfix component process.
Postfix-script: This contains some postfix commands, so that we can
Securely execute these postfix commands.
　　
You only need to configure these configuration files when configuring/etc/postfix/mail. cf.
　　
5. Q: What should I do with aliases under sendmail?
　　
A: You can copy the aliases file of sendmail backed up before installing postfix to/etc/postfix/aliases. if the configuration in cf is correct, enter newaliases to convert the file to the db file.
　　
6. Q: I used majordomo and all my aliases are in/etc/mail/majordomo. What should I do?
　　
A: copy the previously used majordomo file to/etc/postfix/majordomo, and ensure that the file is in mail. in cf # alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases is not commented out. modify this line to # alias_database = hash: /etc/aliases, hash:/etc/postfix/majordomo. After saving and exiting, run newaliases. If bulk_mailer is used, you need to make some modifications to your majordomo aliases.
　　
7. Q: What mail delivery agent (MDA) is used for postfix )?
　　
A: postfix can be configured to use different MDA software. In Red Hat Linux, the default MDA software is procmail, and procmail is very useful for Red Hat Linux and postfix, there is no reason to use other MDA software. You can use rpm-q procmail to check whether procmail is installed on your system.
　　
8. Q: How can I make postfix not respond to verify requests for postfix security?
　　
A: By default, postfix does not respond to verify requests. It is not necessary to send an email to check whether the user exists. See the following example:
[Root @ linuxserver/] # telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 linuxserver.test.com ESMTP Postfix PostFix-v.2000
Helo localhost
250 linuxserver.test.com
Vrfy testuser
252 Send mail to find out
Quit
221 Bye
Connection closed by foreign host.
[Root @ linuxserver/] #
　　
9. Q: How can I use the virtual domains I set in sendmail under postfix?
　　
A: It is much easier to use A virtual domain in postfix than to configure sendmail. It does not use m4 for processing and is an easy-to-understand E-file. First, go to/etc/postfix/mail. in cf, configure your virtual domain as the correct forwarding and receiving domain and modify/etc/postfix/main. the mydestination parameter in cf. By default, postfix accepts emails that meet the following conditions: the email with the destination of $ inet_interfaces, the email with the destination of $ mydestination, And the email with the destination of $ virtual_maps. Modify/etc/postfix/mail. in the cf file, the parameter virtual_maps = hash:/etc/postfix/virtual. If/etc/postfix/virtual does not exist, create a new one. The following is an example of a virtual file:
[Root @ linuxserver/] cat/etc/postfix/virtual
Linux.net, abc.com, cc123.org, ppp.com
　　
10. Q: How can I make my configuration take effect in postfix?
　　
A: postfix reload as the root user
　　
11. Q: How do I refresh the mail queue in postfix?
　　
A: postfix flush as the root user
　　
12. Q: I must use some map files to set access files and mailertable. How can I convert these files to. db format?
　　
A: As the root user, postmap/etc/postfix/access postmap or/etc/postfix/mailertable
　　
13. Q: How can I enable the postfix to run it on my own after it is started?
　　
A: You can use the ntsysv tool to select postfix.
　　
14. Q: How do I set the queue latency of postfix?
　　
A: You can modify the following parameters in the main configuration file/etc/postifx/main. cf of postfix:
Queue_run_delay (default value: 1000 seconds)
# Set how long the queue management process will scan for undeliverable emails
Maximal_queue_lifetime (default value: 5 days)
# Set the maximum time for an email in the queue
Minimal_backoff_time (default value: 1000 seconds)
# Emails cannot be locked during this time
Maximal_backoff_time (4000 seconds by default)
# After this time, if the email is still not delivered, it is considered as unable to be delivered.
Qmgr_message_recipient_limit (1000 by default)
　　
15. Q: How do I disable postfix from performing reverse domain name resolution on the Client IP address?
　　
A: Log On As the root user.
Postconf-e disable_client_dns_lookup = 1
Postfix reload
　　
16. Q: Do you have any tools to help me analyze my postfix logs?
　　
A: James S. seymour wrote a pflogsumm in perl. the pl script can be downloaded here: http://jimsun.linxnet.com/postfix_contrib.html. then, you can download the following content in crontab: 0 2 ***/path/to/pflogsumm. pl-d today/var/log/maillog | mail-s "Mail Report" you@youdomain.com regularly sends the analysis Report to you, other use parameters can see pflogsumm. pl information.