Starting Guide for Postfix Mail Server Configuration Supporting Anti Spam and Anti Virus

Dr. Hidaia Mahmood Alassouli

• Publisher: Dr. Hidaia Mahmood Alassouli
• Year: 2021
• eBook ISBN: 9783985512065
• Topic: Computer Science
• Subtopic: System Administration
• Index: Computer Science

This work provides starting guide for simple Postfix mail server configuration. Then I configured the Postfix mail server to support Anti-Spam and Anti-Virus, using two methods.• Method 1: With Postfix, SpamAssassin, ClamAV and Amavis-new• Method 2: With Postfix, SpamAssassin, ClamAV and ProcmailThe report includes the following sections1. How Postfix receives mail: 2. How Postfix delivers mail3. Starting guide for quick Postfix configuration4. Postfix mail server and Dovecot configuration5. Installing ClamAV and SpamAssassin6. Installing and configuring Squirrelmail: 7. Method 1 to support Antivirus and Antispam: Using Postfix, Amavis-new, ClamAV, SpamAssassin8. Method 2 to support Antivirus and Antispam: Using Postfix, Procmail, ClamAV, SpamAssassin

8. Method 1 to support Antivirus and Antispam: Using Postfix, Amavis-new, ClamAV, SpamAssassin

This is just example to support the Antivirus and Antispam on the Postfix server. You must change the IP and domain names to your desired IPs and domain names:

1- Configure the Postfix with general configuration options. I wrote a previous report in Postfix, so no need to repeat.

In /etc/postfix/main.cf

myhostname = linux1.localdomain.msft

mydomain = localdomain.msft

myorigin = $myhostnam

inet_interfaces = all

mydestination = $myhostname, localhost.$mydomain $mydomain

mynetworks_style = subnet

content_filter = smtp-amavis:[127.0.0.1]:10024

transport_maps = hash:/etc/postfix/transport

relay_domains = $transport_maps, $mydestination

In /etc/postfix/master.cf, add

smtp-amavis unix - - - - 2 smtp -o smtp_data_done_timeout=1200 -o disable_dns_lookups=yes

localhost:10025 inet n - - - - smtpd -o content_filter=

In /etc/postfix/transport

.localdomain.msft local:

2- Then, make

# postmap transport

# service postfix restart

# service postfix reload

3- Download amavis-new-2.4.0 from www.ijs.si/software/amavisd, and extract it

4- Fellow the installation requirements in the help files,

• 4.1- Install the following webmin modules using the webmin (go to Others, then Perl Modules)

Archive::Tar (Archive-Tar-x.xx)

Archive::Zip (Archive-Zip-x.xx) (1.14 or later should be used!)

Compress::Zlib (Compress-Zlib-x.xx) (1.35 or later)

Convert::TNEF (Convert-TNEF-x.xx)

Convert::UUlib (Convert-UUlib-x.xxx) (1.05 or later, stick to new versions!)

MIME::Base64 (MIME-Base64-x.xx)

MIME::Parser (MIME-Tools-x.xxxx) (latest version from CPAN - currently

5.417)

Mail::Internet (MailTools-1.58 or later have workarounds for Perl 5.8.0 bugs)

Net::Server (Net-Server-x.xx) (version 0.88 finally does setuid right)

Net::SMTP (libnet-x.xx, ports/net/p5-Net) (>= libnet-1.16 for performance)

Digest::MD5 (Digest-MD5-x.xx) (2.22 or later)

IO::Stringy (IO-stringy-x.xxx)

Time::HiRes (Time-HiRes-x.xx) (use 1.49 or later, older can cause problems)

Unix::Syslog (Unix-Syslog-x.xxx)

BerkeleyDB with bdb library 3.2 or later (4.2 or later preferred)

Optional Perl modules:

Mail::SpamAssassin for doing spam scanning (2.64 or 3.0.4 or >=3.1)

DBI with appropriate DBD::* if using SQL lookups

Net::LDAP if using LDAP lookups

Authen::SASL authenticating on mail forwarding and on submitting DSN

Mail::ClamAV Perl module interface to ClamAV library

SAVI Perl module interface to Sophos library (0.30 or later)

• 4.2- Create a user and group amavis, the home directory /var/amavis. Create its home directory, unless account creation procedure already did it:

# mkdir /var/amavis

Create the following subdirectories:

# mkdir /var/amavis/tmp /var/amavis/var /var/amavis/db /var/amavis/home

Do

# chown -R amavis:amavis /var/amavis

# chmod -R 750 /var/amavis

• 4.4- Do

# cp amavisd /usr/local/sbin/ (from the amavis directory)

# chown root /usr/local/sbin/amavisd

# chmod 755 /usr/local/sbin/amavisd

• 4.5- Copy file amavisd.conf to wherever you want it to reside such as /etc, and make sure it is not writable by non-privileged users;

# cp amavisd.conf /etc/

# chown root /etc/amavisd.conf

# chmod 644 /etc/amavisd.conf

• 4.6- Create a directory (e.g. /var/virusmails) to be used by amavisd-new as a quarantine area (if a virus or spam quarantine is desired).

# mkdir /var/virusmails

# chown amavis:amavis /var/virusmails

# chmod 750 /var/virusmails

• 4.7- Make the following

# chown root /var/amavis

# chown -R amavis:amavis /var/amavis/var

# chmod 750 /var/amavis /var/amavis/var

• 4.8- Make the following inside the amaisd-new directory to restart the amavisd service at boot time.

# cp amavisd_init.sh /etc/rc.d/init.d/amavisd

# chmod 755 /etc/rc.d/init.d/amavisd

# chkconfig --level 2345 amavisd on

and change the amavisd_init.sh , so

prog="/usr/local/sbin/amavisd"

• 4.9- Edit file /etc/amavisd.conf , you need to go through the help for proper configuration of the file, as an example:

$max_servers = 2;

$daemon_user = 'amavis';

$daemon_group = 'amavis';

$mydomain = 'localdomain.msft';

$MYHOME = '/var/amavis';

$TEMPBASE = "$MYHOME/tmp";

$ENV{TMPDIR} = $TEMPBASE;

$QUARANTINEDIR = '/var/virusmails';

$db_home = "$MYHOME/db";

$helpers_home = "$MYHOME/var";

$pid_file = "$MYHOME/var/amavisd.pid";

$lock_file = "$MYHOME/var/amavisd.lock";

$myhostname = 'linux1.localdomain.msft'; # must be a fully-qualified domain name!

$notify_method = 'smtp:[127.0.0.1]:10025';

$forward_method = 'smtp:[127.0.0.1]:10025'; # set to undef with milter!

$inet_socket_port = 10024;

$final_virus_destiny = D_BOUNCE;

$final_banned_destiny = D_BOUNCE;

$final_spam_destiny = D_BOUNCE;

$final_bad_header_destiny = D_PASS;

$inet_socket_bind = '127.0.0.1'; # limit socket bind to loopback interface

# (default is '127.0.0.1')

@inet_acl = qw(127.0.0.1 [:...

Table of contents

• Starting Guide for Postfix Mail Server Configuration Supporting Anti Spam and Anti Virus
• 2. How Postfix receives mail:
• 3. How Postfix delivers mail
• 4. Starting guide for Postfix configuration:
• 5. Postfix mail server and Dovecot configuration:
• 6. Installing and configuring Squirrelmail:
• 7. Installing ClamAV and SpamAssassin
• 8. Method 1 to support Antivirus and Antispam: Using Postfix, Amavis-new, ClamAV, SpamAssassin
• 9. Method 2 to support Antivirus and Antispam : Using Postfix, Procmail, ClamAV, SpamAssassin