Building A Reliable Open Source Mail Server

This tutorial is one of many available on the Internet. The focus here is on ease of implementation, avoidance of heavy customization (compiling from source, long config files), and software manageability (all RPM based).


o no licenses
o open source GNU software
o secure online interface using SSL
o minimal hardware requirements
o server side Spam filtering

Bundled Distribution Software Requirements
o Fedora Core 1 with the following packages:
    o Apache
    o PHP
    o Postfix
    o wget
    o Squirrelmail

Unbundled Software Requirements
o Apt 0.5.15 (
o Courier IMAP 2.2.1 (
o Maildrop 1.6.3 (
o SpamAssassin 2.63-1 (
o perl-Mail-Spamassassin 2.63-1 (
o Anomy Mail Tools 1.66 (
o Subjadd (
o Squirrelmail 1.4.2-1 (

Remove if already installed
o SpamAssassin
o perl-Mail-Spamassassin

Software Not Used
o MySQL, PostgreSQL

Account Management and Mailboxes
o standard user accounts via the /etc/passwd and /etc/shadow files

Examples used in this tutorial need to be replaced with the relevant values

I. Download and Install the APT Package Manager for RPM from 

This package manager ensures easy installation of any needed software and is much faster than up2date/Fedora mirrors.

$ su -
# wget
# wget
# rpm -ivh apt*
The postgres, mysql, and openldap packages are only needed to satisfy Courier Imap spec files. These packages will not
 be needed or installed.
# apt-get update
# apt-get install postgresql-devel
# apt-get install mysql-devel
# apt-get install openldap-servers
# apt-get install perl-Digest-SHA1
# exit
II. Build the RPM Development Directory Structure for Courier Imap and Maildrop

The Courier Imap and Maildrop packages come bundled with preconfigured spec files. They can be built as a regular user
straight from the source zip files.

$ mkdir rpmbuild
$ cd rpmbuild
$ cd RPMS
$ mkdir i386 i586 i686
$ cd ../SRPMS
$ mkdir i386 i586 i686
$ cd $HOME
$ vi .rpmmacros
%_topdir %(echo $HOME)/rpmbuild
%debug_package %{nil}
III. Build the Courier IMAP and Maildrop RPM Packages
$ cd $HOME
$ wget
$ wget
$ rpmbuild -ta courier-imap-2.2.1.tar.bz2
$ rpmbuild -ta maildrop-1.6.3.tar.bz2
$ cd rpmbuild/RPMS/i386
$ su
IV. Install and Enable the Courier IMAP and Maildrop Services
# rpm -ivh courier-imap-2.2.1-1.1.i386.rpm maildrop-*
# chkconfig --add courier-imap
# chkconfig courier-imap on
# service courier-imap start
V. Configure Postfix and Integrate it with Postfix

This is a very basic configuration for Postfix to get it running and configured to integrate with Maildrop. The parameters listed
 are the ONLY ones
that need to be changed.
# vi /etc/postfix/
myhostname =
mydomain =
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, $mydomain
mailbox_command = /usr/bin/maildrop -d "$USER" -f "$SENDER" "$EXTENSION"

# cp /etc/aliases /etc/postfix/aliases
# chkconfig postfix on
# service postfix start
# exit
VI. Download and Install SpamAssassin
$ cd $HOME/rpmbuilds/RPMS/i386
$ wget
$ wget
$ wget
$ su
# rpm -ivh perl-Mail*
# rpm -ivh spamassassin*
# chkconfig spamassassin on
# service spamassassin start
VII. Integrate Maildrop with SpamAssassin
# vi /etc/maildroprc
import SENDER
xfilter "/usr/bin/spamc -f"
# exit
Setup a regular user to receive email. The maildirmake command is part of the Maildrop package. It creates Qmail style mailboxes 
which are traditionally faster than standard Unix mbox formats.
# su - darren
$ maildirmake Maildir
$ maildirmake -f Spam Maildir
$ vi $HOME/.mailfilter
if ( /^X-Spam-Status: Yes/ )
cc "!"
to "Maildir/.Spam"
$ chmod 600 $HOME/.mailfilter
VIII. Integrate SpamAssassin with Anomy Mail Tools

Modify the "Unicode UTF-8" locales in /etc/sysconfig/i18n. There have been numerous issues with Anomy, Perl, and formatting as
 a result. See

for more details.

# vi /etc/sysconfig/i18n
Download Anomy Mail Tools
# cd /usr/local
# wget
# gunzip anomy*
# tar xvf anomy*
# vi /etc/maildroprc
import SENDER
xfilter "/usr/bin/spamc -f"
xfilter "/usr/local/anomy/bin/ /usr/local/anomy/anomy.conf 2>>~/mailfilter-log.txt | cat"
# cd /usr/local/anomy
# wget

Download the "subjadd" Utility
# cd /usr/local/anomy/bin
# wget
# gunzip subjadd.gz
# su - darren
$ vi .mailfilter
if ( /^X-Spam-Status: Yes/ )
cc "!"
to "Maildir/.spam"
if ( /^*** Attached file dropped ***/:b )
cc "Maildir/.Virus"
xfilter "/usr/local/anomy/bin/subjadd [Virus-Detected]"
to "Maildir"
$ maildirmake -f Virus Maildir
IX. Install and configure Squirrelmail for Courier IMAP
$ cd $HOME/rpmbuild/RPMS/i386
$ wget
$ su
# rpm -Uvh squirrlemail*

# cd /usr/share/squirrelmail/conf
# ./


D. Set pre-defined settings for specific IMAP servers

Command >> D
SquirrelMail Configuration : Read: config.php


Please select your IMAP server:
cyrus = Cyrus IMAP server
uw = University of Washington's IMAP server
exchange = Microsoft Exchange IMAP server
courier = Courier IMAP server
macosx = Mac OS X Mailserver
quit = Do not change anything
Command >> courier

imap_server_type = courier
default_folder_prefix = INBOX.
trash_folder = Trash
sent_folder = Sent
draft_folder = Drafts
show_prefix_option = false
default_sub_of_inbox = false
show_contain_subfolders_option = false
optional_delimiter = .
delete_folder = true

Press any key to continue...


Command >> S

Data saved in config.php
Press enter to continue...


Command >> q
X. Configure Apache

This is a very basic configuration of an Apache webserver using "name based" virtual hosting. These variables are the ONLY
 ones that need to be changed.

# vi /etc/httpd/conf/httpd.conf
NameVirtualHost *:80
<VirtualHost *:80>
DocumentRoot /var/www/html/example
ErrorLog logs/error_log
CustomLog logs/access_log common

# mkdir /var/www/html/example
# mkdir /var/www/html/example/logs
# touch /var/www/html/example/logs/access_log
# touch /var/www/html/example/logs/error_log
# chown -R apache:apache /var/www/html/example/logs/

XII. Debug Messages

An approrpiately delivered message should log this entry:

# tail -f /var/log/maillog
Mar 17 21:44:09 asaph postfix/smtpd[30781]: connect from[]
Mar 17 21:44:10 asaph postfix/smtpd[30781]: 600E33A7F3:[]
Mar 17 21:44:10 asaph postfix/cleanup[30783]: 600E33A7F3: message-id=<2050.
Mar 17 21:44:10 asaph postfix/smtpd[30781]: disconnect from[]
Mar 17 21:44:10 asaph postfix/nqmgr[30707]: 600E33A7F3: from=<>, size=1009,
 nrcpt=1 (queue active)
Mar 17 21:44:10 asaph spamd[30274]: connection from asaph [] at port 32906
Mar 17 21:44:11 asaph spamd[30788]: info: setuid to darren succeeded
Mar 17 21:44:11 asaph spamd[30788]: Creating default_prefs [/home/darren/.spamassassin/user_prefs]
Mar 17 21:44:11 asaph spamd[30788]: Created user preferences file: /home/darren/.spamassassin/user_prefs
Mar 17 21:44:11 asaph spamd[30788]: processing message <2050.>
for darren:500.
Mar 17 21:48:26 asaph postfix/local[30814]: B0F7C3B1F7: to=<>, relay=local, delay=1,
status=sent ("|/usr/bin/maildrop -d "$USER" -f "$SENDER" "$EXTENSION")

Links and References:

Thanks to Robin Whittle ( for great documentation on all of this!