Nasim Mansurov

16) Courier-IMAP Installation
First, we’ll install Courier-IMAP to /usr/lib/courier-imap. Then, we will configure it to work with VMailMgr by changing the password checker (authvmailmgr).

# cd /usr/local/src
# bzip2 -d courier-imap-3.0.8.tar.bz2
# tar xf courier-imap-3.0.8.tar
# cd courier-imap-3.0.8
# ./configure –disable-root-check
# make
# make install

If you are using RedHat Linux, don’t forget to add –with-redhat at the end of the configure line, otherwise configure will terminate with a warning.

It will take a while for the configure script to be done. When I installed courier for the first time, I thought that the script was looping and something went wrong, so I terminated it. Don’t do that - it looks like the script does the same thing over and over again, so just be a little patient and wait.

Courier-IMAP has its own authentication scheme which needs to be changed for our installation. This is what we need to do:

# cd /usr/local/src/vmailmgr-0.97
# cp authenticate/authvmailmgr /usr/lib/courier-imap/libexec/authlib
# cd /usr/lib/courier-imap/etc
# cp imapd.dist imapd
# cp imapd-ssl.dist imapd-ssl
# vi imapd

While editing the file imapd, change “MAXPERIP”(Maximum connections per IP) to 20. Then, change “AUTHMODULES” (Authentication modules) and “AUTHMODULES_ORIG” to “authvmailmgr relay-ctrl-allow”. Save and close the file.

Now do “cp authdaemonrc.dist authdaemonrc” and edit the file authdaemonrc, delete the line that says authmodulelist=”authcustom……..” and insert authmodulelist=”authvmailmgr relay-ctrl-allow”. Save and close the file.

Next, do the following:

# cd /usr/lib/courier-imap/libexec/authlib
# mv authdaemond authdaemond.old
# ln -s /usr/local/bin/relay-ctrl-allow relay-ctrl-allow
# echo ‘#! /bin/sh’ > authdaemond
# echo ‘DIR=`dirname $0`’ >> authdaemond
# echo ‘AUTHDAEMOND=authdaemond.plain’ >> authdaemond
# echo ‘. /usr/lib/courier-imap/etc/authdaemonrc’ >> authdaemond
# echo ‘if test “$version” != “”‘ >> authdaemond
# echo ‘then’ >> authdaemond
# echo ‘ AUTHDAEMOND=”$version”‘ >> authdaemond
# echo ‘fi’ >> authdaemond
# chmod 755 authdaemond

Now edit imapd.rc and make some minor changes to work with relay-ctrl:

# vi /usr/lib/courier-imap/libexec/imapd.rc

Search for “/usr/lib/courier-imap/libexec/couriertcpd -address=$ADDRESS” line and insert “/usr/local/bin/envdir /etc/relay-ctrl /usr/local/bin/relay-ctrl-chdir \” above it. Thus, relay-ctrl will get initialized before “couriertcpd” is called.

Let’s run the IMAP server and see if it works fine:

# /usr/lib/courier-imap/libexec/imapd.rc start
# ps ax | grep courier
1698 ? S 0:00 /usr/lib/courier-imap/libexec/couriertcpd -address=0 -stderrlogger…
1711 ? S 0:00 /usr/lib/courier-imap/libexec/courierlogger imapd

The command ps ax should return two lines. If the two lines are present, then everything is running properly. It is now time to test the IMAP server. Let’s set up another test mail account on a windows box and e-mail client. Only this time, instead of specifying POP3, we specify IMAP server. After the account is all set, check if it works. Your client should be able to download the IMAP directory structure to your PC. If it does not work for some reason, or your password gets denied - you did something wrong. My recommendation to you then is to recheck the guide again and make sure that you do everything right.

Assuming that everything worked just fine, we’ll take another step forward - installing Qmail extras.

17.1) MailDrop, TNEF, SpamAssassin + Perl Utils Installation
Since we’ll be running a mail scanner utility to check for spam and viruses, some tools must be installed. Let’s start with the first one - MailDrop.

# cd /usr/local/src
# bzip2 -d maildrop-2.0.4.tar.bz2
# tar xf maildrop-2.0.4.tar
# cd maildrop-2.0.4
# ./configure
# make
# make install-strip
# make install-man

Now TNEF unpacker. This program is used by Qmail-Scanner, which we will
be installing later.

# cd /usr/local/src
# tar zxf tnef-1.4.4.tar.gz
# cd tnef-1.4.4
# ./configure
# make
# make check
# make install

Installing SpamAssassin is very easy. You must have Perl installed and fully operational in order to be able to build and install SpamAssassin. If you prefer installing Perl modules from sources, get SpamAssassin source file from the location specified above and run the commands “perl Makefile.PL” “make” “make test” and “make install” respectively. Otherwise, my recommendation is to install from CPAN shell. Execute the following command in shell:

# perl -MCPAN -eshell

After the command is executed, you’ll be presented to the cpan prompt*. Just type install Mail::SpamAssassin and press Enter. Cpan will start downloading the sources from other servers and install SpamAssassin for you. If you get a dependency warning, accept the default “yes” and let cpan install whatever is needed.

* If you’ve never used perl CPAN, you will be presented with a perl configuration script, which will ask some questions regarding the installation of CPAN module. Just accept the defaults and specify the closest location for your source downloads. When the process is complete, you should be able to type commands in the cpan prompt. Type install Bundle::CPAN to get and install the latest CPAN modules.

If you get an error saying something like “Makefile:91: *** missing separator. Stop.” in Redhat Linux 9, edit the file /etc/sysconfig/i18n and replace LANG=”en_US.UTF-8″ with LANG=”en_US”. This helped me to cure module installations.

Furthermore, don’t forget to install the following Perl Modules (from sources or CPAN):

Time::HiRes
DB_File
Sys::Syslog

Running Perl SpamAssassin on every mail call is expensive and inefficient which is why a separate “spamd” daemon written in C is included in SpamAssassin package. To get spamd up and running, we will have to first cd to the SpamAssassin source directory. If you have downloaded SpamAssassin and installed it from shell, type the following in shell prompt:

# cd /usr/local/src/Mail-SpamAssassin-3.2.5/spamd
# cp redhat-rc-script.sh /etc/rc.d/init.d/spamd
# chmod 755 /etc/rc.d/init.d/spamd
# chkconfig –add spamd
# chkconfig spamd on

The spam daemon (spamd) must be run as “qmaill” user, otherwise you will get permission errors. Modify spamd init script (/etc/init.d/spamd) and add “-u qmaill” to the end of “SPAMDOPTIONS”. Save the file and type:

# /etc/init.d/spamd start
Starting spamd: [ OK ]

If you have installed from CPAN, then change the first line to “cd /root/.cpan/build/Mail-SpamAssassin-3.2.5/spamd”.
Of course, you should not forget about changing the installation script name (redhat-rc-script.sh in this case) to whatever platform you are installing on.

Now perform the last step to make spamassassin work under qmail-scanner:

# cd /var/qmail
# mkdir .spamassassin
# chmod 700 .spamassassin
# chown qmaill:qmail .spamassassin
# cd .spamassassin
# echo ‘required_hits 5′ > user_prefs
# chown qmaill:qmail user_prefs

Attention: In some cases, only changing ownership to qmailq:qmail will make spamassassin work.

Make sure that /etc/mail/spamassassin/local.cf exists (should be created during the install). If it doesn’t, create it and copy-paste the following into the file:

required_score 5.0
rewrite_header Subject *****SPAM*****
lock_method flock
use_bayes 1
bayes_auto_learn 1

17.2) ClamAV Antivirus
Warning: Please skip this step if you have less than 256 MB RAM on your mail server! Running antivirus on every single mail message will definitely slow down your server and might consume too much memory. It gets especially dangerous if your server is under heavy load or if you have many simultaneous mail users. The best configuration is 1 GB of RAM used solely for mail delivery purposes.

I have tested many different antivirus programs for Qmail, and the best one is clearly ClamAV. I used sophos & sophie combination before, but it’s not free anymore…

First, download ClamAV Antivirus from www.clamav.net. Place it in /usr/local/src and execute the following commands:

# cd /usr/local/src
# tar zxf clamav-0.93.3.tar.gz
# groupadd clamav
# useradd -c “Clam AntiVirus Account” -g clamav -s /bin/false clamav
# ./configure
# make
# make install

ClamAV should be installed. Run “clamd –version” to see if it works. If you got a response with the version number, go ahead and edit /usr/local/etc/clamd.conf and /usr/local/etc/freshclam.conf to suit your scanning needs. Then it’s time to update the virus definitions:

# mkdir /var/lib/clamav
# chown clamav:clamav /var/lib/clamav
# touch /var/log/freshclam.log
# chmod 600 /var/log/freshclam.log
# chown clamav /var/log/freshclam.log
# clamd
# freshclam -d -c 6 -l /var/log/freshclam.log

Don’t forget to add “clamd” and “freshclam -d -c 6 -l /var/log/freshclam.log” into your startup scripts.

18) Final touch - Qmail-Scanner
This is the last step we’ll take to finish the installation - installing and configuring Qmail-Scanner. Execute the following commands in shell:

# cd /usr/local/src
# tar zxf qmail-scanner-2.05.tgz
# cd qmail-scanner-2.05
# groupadd qscand
# useradd -c “Qmail-Scanner Account” -g qscand -s /bin/false qscand
# ./configure –spooldir /var/qmail/qmailscan \
–qmaildir /var/qmail –admin login –domain yourserver.com \
–local-domains “domain.one.com,domain.two.com” –install
Building Qmail-Scanner 1.23…

This script will search your system for the virus
scanners it knows about, and will ensure that all
external programs qmail-scanner-queue.pl uses are
explicitly pathed for performance reasons.

Continue? ([Y]/N)

Don’t forget to change “login” to your login and “yourserver.com” to your default domain. Also change “domain.one.com,domain.two.com” to whatever other domains you have on your system. If you only have one domain, specify one and get rid of everything after comma. If you have more than two domains, don’t forget to separate them with a “,” (comma). Press enter afterwards and answer “Y” when it asks you to Continue.

Qmail-Scanner should be able to detect “spamd” (SpamAssassin) and “sophie” (Antivirus) if you installed it. It will create directories under
/var/qmail/qmailscan and change necessary file ownerships. Then, do the following:

# /usr/local/bin/setuidgid qmaill \
“/var/qmail/bin/qmail-scanner-queue.pl” -g
perlscanner: generate new DB file
perlscanner: total of 9 entries.

If the above doesn’t work for you and produces an error, try changing “qmaill” to “qmailq”. If changing to “qmailq” works, you’ll most probably have to modify permissions for spamassassin and sophie as well. This is a weird behavior that I’m unable to figure out.

Type /usr/local/bin/setuidgid qmaill “contrib/test_installation.sh -doit” and then check your e-mail. If you received three messages, everything is running properly :-) If you haven’t received anything, view /var/qmail/qmailscan/qmail-queue.log for clues. If something fails and you are receiving a “451 qq temporary problem”, check ownership and permissions for /var/qmail/qmailscan. The directory owner should be qmaill:qmail and permissions should be set to 770.

Attention: In some cases, only changing ownership to qmailq:qmail will make qmail-scanner work. My recommendation is to always check the logs - most of the problems will be spotted from there.

Change “$DEBUG=1″ to “$DEBUG=0″ in /var/qmail/bin/qmail-scanner-queue.pl - this will disable Qmail-Scanner’s dumping of every single message delivery process to qmail-queue.log. Furthermore, if you want messages identified as spam to be “seen” as spam messages (very useful for filtering mail), find the line “my $spamc_subject=”;” and change it to “my $spamc_subject=’POTENTIAL SPAM:’;”. You could then setup your email client to deliver messages with words “POTENTIAL SPAM” to other mailboxes or automatically move them to trash. Sweet huh?

Phew…Qmail is now installed and fully operational :-)

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Posted by MegaZ on 12/20/2002.