Virtual Users And Domains With Postfix, Courier And MySQL (Ubuntu 7.10) - Page 4

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Submitted by falko (Contact Author) (Forums) on Thu, 2007-11-22 17:43. ::

9 Install amavisd-new, SpamAssassin, And ClamAV

To install amavisd-new, spamassassin and clamav, run the following command:

apt-get install amavisd-new spamassassin clamav clamav-daemon zoo unzip bzip2 unzoo libnet-ph-perl libnet-snpp-perl libnet-telnet-perl nomarch lzop pax

Afterwards we must configure amavisd-new. The configuration is split up in various files which reside in the /etc/amavis/conf.d directory. Take a look at each of them to become familiar with the configuration. Most settings are fine, however we must modify three files:

First we must enable ClamAV and SpamAssassin in /etc/amavis/conf.d/15-content_filter_mode by uncommenting the @bypass_virus_checks_maps and the @bypass_spam_checks_maps lines:

vi /etc/amavis/conf.d/15-content_filter_mode

The file should look like this:

use strict;

# You can modify this file to re-enable SPAM checking through spamassassin
# and to re-enable antivirus checking.

#
# Default antivirus checking mode
# Uncomment the two lines below to enable it back
#

@bypass_virus_checks_maps = (
   \%bypass_virus_checks, \@bypass_virus_checks_acl, \$bypass_virus_checks_re);


#
# Default SPAM checking mode
# Uncomment the two lines below to enable it back
#

@bypass_spam_checks_maps = (
   \%bypass_spam_checks, \@bypass_spam_checks_acl, \$bypass_spam_checks_re);

1;  # insure a defined return

And then you should take a look at the spam settings and the actions for spam-/virus-mails in /etc/amavis/conf.d/20-debian_defaults. There's no need to change anything if the default settings are ok for you. The file contains many explanations so there's no need to explain the settings here:

vi /etc/amavis/conf.d/20-debian_defaults

[...]
$QUARANTINEDIR = "$MYHOME/virusmails";

$log_recip_templ = undef;    # disable by-recipient level-0 log entries
$DO_SYSLOG = 1;              # log via syslogd (preferred)
$syslog_ident = 'amavis';    # syslog ident tag, prepended to all messages
$syslog_facility = 'mail';
$syslog_priority = 'debug';  # switch to info to drop debug output, etc

$enable_db = 1;              # enable use of BerkeleyDB/libdb (SNMP and nanny)
$enable_global_cache = 1;    # enable use of libdb-based cache if $enable_db=1

$inet_socket_port = 10024;   # default listenting socket

$sa_spam_subject_tag = '***SPAM*** ';
$sa_tag_level_deflt  = 2.0;  # add spam info headers if at, or above that level
$sa_tag2_level_deflt = 6.31; # add 'spam detected' headers at that level
$sa_kill_level_deflt = 6.31; # triggers spam evasive actions
$sa_dsn_cutoff_level = 10;   # spam level beyond which a DSN is not sent

$sa_mail_body_size_limit = 200*1024; # don't waste time on SA if mail is larger
$sa_local_tests_only = 0;    # only tests which do not require internet access?

[...]
$final_virus_destiny      = D_DISCARD;  # (data not lost, see virus quarantine)
$final_banned_destiny     = D_BOUNCE;   # D_REJECT when front-end MTA
$final_spam_destiny       = D_BOUNCE;
$final_bad_header_destiny = D_PASS;     # False-positive prone (for spam)
[...]

Finally, edit /etc/amavis/conf.d/50-user and add the line $pax='pax'; in the middle:

vi /etc/amavis/conf.d/50-user

use strict;

#
# Place your configuration directives here.  They will override those in
# earlier files.
#
# See /usr/share/doc/amavisd-new/ for documentation and examples of
# the directives you can use in this file
#

$pax='pax';

#------------ Do not modify anything below this line -------------
1;  # insure a defined return

Afterwards, run these commands to add the clamav user to the amavis group and to restart amavisd-new and ClamAV:

adduser clamav amavis
/etc/init.d/amavis restart
/etc/init.d/clamav-daemon restart
/etc/init.d/clamav-freshclam restart

Now we have to configure Postfix to pipe incoming email through amavisd-new:

postconf -e 'content_filter = amavis:[127.0.0.1]:10024'
postconf -e 'receive_override_options = no_address_mappings'

Afterwards append the following lines to /etc/postfix/master.cf:

vi /etc/postfix/master.cf

[...]
amavis unix - - - - 2 smtp
        -o smtp_data_done_timeout=1200
        -o smtp_send_xforward_command=yes

127.0.0.1:10025 inet n - - - - smtpd
        -o content_filter=
        -o local_recipient_maps=
        -o relay_recipient_maps=
        -o smtpd_restriction_classes=
        -o smtpd_client_restrictions=
        -o smtpd_helo_restrictions=
        -o smtpd_sender_restrictions=
        -o smtpd_recipient_restrictions=permit_mynetworks,reject
        -o mynetworks=127.0.0.0/8
        -o strict_rfc821_envelopes=yes
        -o receive_override_options=no_unknown_recipient_checks,no_header_body_checks
        -o smtpd_bind_address=127.0.0.1

Then restart Postfix:

/etc/init.d/postfix restart

Now run

netstat -tap

and you should see Postfix (master) listening on port 25 (smtp) and 10025, and amavisd-new on port 10024:

root@server1:/etc/postfix# netstat -tap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 localhost.localdo:10024 *:*                     LISTEN     14770/amavisd (mast
tcp        0      0 localhost.localdo:10025 *:*                     LISTEN     15800/master
tcp        0      0 localhost.localdo:mysql *:*                     LISTEN     5742/mysqld
tcp        0      0 *:smtp                  *:*                     LISTEN     15800/master
tcp6       0      0 *:imaps                 *:*                     LISTEN     13290/couriertcpd
tcp6       0      0 *:pop3s                 *:*                     LISTEN     13359/couriertcpd
tcp6       0      0 *:pop3                  *:*                     LISTEN     13320/couriertcpd
tcp6       0      0 *:imap2                 *:*                     LISTEN     13253/couriertcpd
tcp6       0      0 *:www                   *:*                     LISTEN     4961/apache2
tcp6       0      0 *:ssh                   *:*                     LISTEN     3725/sshd
tcp6       0      0 server1.example.com:ssh ::ffff:192.168.0.2:4670 ESTABLISHED3783/0
root@server1:/etc/postfix#

 

10 Install Razor, Pyzor And DCC And Configure SpamAssassin

Razor, Pyzor and DCC are spamfilters that use a collaborative filtering network. To install them, run

apt-get install razor pyzor dcc-client

Now we have to tell SpamAssassin to use these three programs. Edit /etc/spamassassin/local.cf and add the following lines to it:

vi /etc/spamassassin/local.cf

[...]
#dcc
use_dcc 1
dcc_path /usr/bin/dccproc

#pyzor
use_pyzor 1
pyzor_path /usr/bin/pyzor

#razor
use_razor2 1
razor_config /etc/razor/razor-agent.conf

#bayes
use_bayes 1
use_bayes_rules 1
bayes_auto_learn 1

Then we must enable the DCC plugin in SpamAssassin. Open /etc/spamassassin/v310.pre and uncomment the loadplugin Mail::SpamAssassin::Plugin::DCC line:

vi /etc/spamassassin/v310.pre

# This is the right place to customize your installation of SpamAssassin.
#
# See 'perldoc Mail::SpamAssassin::Conf' for details of what can be
# tweaked.
#
# This file was installed during the installation of SpamAssassin 3.1.0,
# and contains plugin loading commands for the new plugins added in that
# release.  It will not be overwritten during future SpamAssassin installs,
# so you can modify it to enable some disabled-by-default plugins below,
# if you so wish.
#
# There are now multiple files read to enable plugins in the
# /etc/mail/spamassassin directory; previously only one, "init.pre" was
# read.  Now both "init.pre", "v310.pre", and any other files ending in
# ".pre" will be read.  As future releases are made, new plugins will be
# added to new files, named according to the release they're added in.
###########################################################################

# DCC - perform DCC message checks.
#
# DCC is disabled here because it is not open source.  See the DCC
# license for more details.
#
loadplugin Mail::SpamAssassin::Plugin::DCC

# Pyzor - perform Pyzor message checks.
#
loadplugin Mail::SpamAssassin::Plugin::Pyzor

# Razor2 - perform Razor2 message checks.
#
loadplugin Mail::SpamAssassin::Plugin::Razor2

# SpamCop - perform SpamCop message reporting
#
loadplugin Mail::SpamAssassin::Plugin::SpamCop

# AntiVirus - some simple anti-virus checks, this is not a replacement
# for an anti-virus filter like Clam AntiVirus
#
#loadplugin Mail::SpamAssassin::Plugin::AntiVirus

# AWL - do auto-whitelist checks
#
loadplugin Mail::SpamAssassin::Plugin::AWL

# AutoLearnThreshold - threshold-based discriminator for Bayes auto-learning
#
loadplugin Mail::SpamAssassin::Plugin::AutoLearnThreshold

# TextCat - language guesser
#
#loadplugin Mail::SpamAssassin::Plugin::TextCat

# AccessDB - lookup from-addresses in access database
#
#loadplugin Mail::SpamAssassin::Plugin::AccessDB

# WhitelistSubject - Whitelist/Blacklist certain subject regular expressions
#
loadplugin Mail::SpamAssassin::Plugin::WhiteListSubject

###########################################################################
# experimental plugins

# DomainKeys - perform DomainKeys verification
#
# External modules required for use, see INSTALL for more information.
# Note that this may be redundant if you also plan to use the DKIM plugin.
#
#loadplugin Mail::SpamAssassin::Plugin::DomainKeys

# MIMEHeader - apply regexp rules against MIME headers in the message
#
loadplugin Mail::SpamAssassin::Plugin::MIMEHeader

# ReplaceTags
#
loadplugin Mail::SpamAssassin::Plugin::ReplaceTags

You can check your SpamAssassin configuration by executing:

spamassassin --lint

It shouldn't show any errors.

Restart amavisd-new afterwards:

/etc/init.d/amavis restart


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