Virtual Users And Domains With Postfix, Courier And MySQL (Fedora 8)
Author: Falko Timme
Last edited 11/14/2007
This tutorial is Copyright (c) 2007 by Falko Timme. It is derived from a tutorial from Christoph Haas which you can find at http://workaround.org. You are free to use this tutorial under the Creative Commons license 2.5 or any later version.
This document describes how to install a mail server based on Postfix that is based on virtual users and domains, i.e. users and domains that are in a MySQL database. I'll also demonstrate the installation and configuration of Courier (Courier-POP3, Courier-IMAP), so that Courier can authenticate against the same MySQL database Postfix uses.
The resulting Postfix server is capable of SMTP-AUTH and TLS and quota (quota is not built into Postfix by default, I'll show how to patch your Postfix appropriately). Passwords are stored in encrypted form in the database (most documents I found were dealing with plain text passwords which is a security risk). In addition to that, this tutorial covers the installation of Amavisd, SpamAssassin and ClamAV so that emails will be scanned for spam and viruses.
The advantage of such a "virtual" setup (virtual users and domains in a MySQL database) is that it is far more performant than a setup that is based on "real" system users. With this virtual setup your mail server can handle thousands of domains and users. Besides, it is easier to administrate because you only have to deal with the MySQL database when you add new users/domains or edit existing ones. No more postmap commands to create db files, no more reloading of Postfix, etc. For the administration of the MySQL database you can use web based tools like phpMyAdmin which will also be installed in this howto. The third advantage is that users have an email address as user name (instead of a user name + an email address) which is easier to understand and keep in mind.
This tutorial is based on Fedora 8 (i386). You should already have set up a basic Fedora system, as described here: http://www.howtoforge.com/fedora-8-server-lamp-email-dns-ftp-ispconfig and http://www.howtoforge.com/fedora-8-server-lamp-email-dns-ftp-ispconfig-p2. Plus, you should make sure that the firewall is off (at least for now) and that SELinux is disabled (this is important!), as shown in the chapters six and seven on http://www.howtoforge.com/fedora-8-server-lamp-email-dns-ftp-ispconfig-p3.
This howto is meant as a practical guide; it does not cover the theoretical backgrounds. They are treated in a lot of other documents in the web.
This document comes without warranty of any kind! I want to say that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!
1 Edit /etc/hosts
Our hostname in this example is server1.example.com, and it has the IP address 192.168.0.100, so we change /etc/hosts as follows:
# Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 localhost.localdomain localhost 192.168.0.100 server1.example.com server1 ::1 localhost6.localdomain6 localhost6
2 Install Some Software
First we import the GPG keys for software packages:
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*
Then we update our existing packages on the system:
Now we install some software that we need later on:
yum groupinstall 'Development Tools'
yum groupinstall 'Development Libraries'
3 Install Apache, MySQL, phpMyAdmin
This can all be installed with one single command (including the packages we need to build Courier-IMAP):
yum install ntp httpd mysql-server php php-mysql php-mbstring rpm-build gcc mysql-devel openssl-devel cyrus-sasl-devel pkgconfig zlib-devel phpMyAdmin pcre-devel openldap-devel postgresql-devel expect libtool-ltdl-devel openldap-servers libtool gdbm-devel pam-devel gamin-devel
4 Install Courier-IMAP, Courier-Authlib, And Maildrop
Unfortunately there are no rpm packages for Courier-IMAP, Courier-Authlib, and Maildrop, therefore we have to install them as described in this tutorial: How To Install courier-imap, courier-authlib, And maildrop On Fedora, RedHat, CentOS
5 Apply Quota Patch To Postfix
We have to get the Postfix source rpm, patch it with the quota patch, build a new Postfix rpm package and install it.
rpm -ivh postfix-2.4.5-2.fc8.src.rpm
The last command will show some warnings that you can ignore:
warning: user kojibuilder does not exist - using root
warning: group kojibuilder does not exist - using root
Now we must edit the file postfix.spec:
Change %define MYSQL 0 to %define MYSQL 1, add Patch0: postfix-2.4.5-vda-ng.patch to the # Patches stanza, and finally add %patch0 -p1 -b .vda-ng to the %setup -q stanza:
[...] %define MYSQL 1 [...] # Patches Patch0: postfix-2.4.5-vda-ng.patch Patch1: postfix-2.1.1-config.patch Patch3: postfix-alternatives.patch Patch6: postfix-2.1.1-obsolete.patch Patch7: postfix-2.1.5-aliases.patch Patch8: postfix-large-fs.patch Patch9: postfix-2.4.0-cyrus.patch Patch10: postfix-2.4.5-open_define.patch [...] %prep %setup -q # Apply obligatory patches %patch0 -p1 -b .vda-ng %patch1 -p1 -b .config %patch3 -p1 -b .alternatives %patch6 -p1 -b .obsolete %patch7 -p1 -b .aliases %patch8 -p1 -b .large-fs %patch9 -p1 -b .cyrus %patch10 -p1 -b .open_define [...]
Then we build our new Postfix rpm package with quota and MySQL support:
rpmbuild -ba postfix.spec
You will see lots of warnings like these that you can ignore:
msg.h:12:1: warning: "/*" within comment
msg.h:14:1: warning: "/*" within comment
msg.h:33:1: warning: "/*" within comment
msg.h:34:1: warning: "/*" within comment
msg.h:35:1: warning: "/*" within comment
msg.h:36:1: warning: "/*" within comment
Our Postfix rpm package is created in /usr/src/redhat/RPMS/i386, so we go there:
shows you the available packages:
[root@server1 i386]# ls -l
-rw-r--r-- 1 root root 3899179 2007-11-13 22:26 postfix-2.4.5-2.fc8.i386.rpm
-rw-r--r-- 1 root root 7907114 2007-11-13 22:26 postfix-debuginfo-2.4.5-2.fc8.i386.rpm
-rw-r--r-- 1 root root 50804 2007-11-13 22:26 postfix-pflogsumm-2.4.5-2.fc8.i386.rpm
Pick the Postfix package and install it like this:
rpm -ivh postfix-2.4.5-2.fc8.i386.rpm
(In case you have problems creating the Postfix rpm package, you can download mine from here.)
6 Set MySQL Passwords And Configure phpMyAdmin
chkconfig --levels 235 mysqld on
Then set passwords for the MySQL root account:
mysqladmin -u root password yourrootsqlpassword
mysqladmin -h server1.example.com -u root password yourrootsqlpassword
Now we configure phpMyAdmin. We change the Apache configuration so that phpMyAdmin allows connections not just from localhost (by commenting out the <Directory /usr/share/phpMyAdmin/> stanza):
# phpMyAdmin - Web based MySQL browser written in php # # Allows only localhost by default # # But allowing phpMyAdmin to anyone other than localhost should be considered # dangerous unless properly secured by SSL Alias /phpMyAdmin /usr/share/phpMyAdmin #<Directory /usr/share/phpMyAdmin/> # order deny,allow # deny from all # allow from 127.0.0.1 #</Directory> # This directory does not require access over HTTP - taken from the original # phpMyAdmin upstream tarball # <Directory /usr/share/phpMyAdmin/libraries> Order Deny,Allow Deny from All Allow from None </Directory> # This configuration prevents mod_security at phpMyAdmin directories from # filtering SQL etc. This may break your mod_security implementation. # #<IfModule mod_security.c> # <LocationMatch "/phpMyAdmin/(.+)"> # SecFilterInheritance Off # </LocationMatch> #</IfModule>
Then we create the system startup links for Apache and start it:
chkconfig --levels 235 httpd on
Now you can direct your browser to http://server1.example.com/phpMyAdmin/ or http://192.168.0.100/phpMyAdmin/ and log in with the user name root and your new root MySQL password.