CentOS 5
Run with Clamav
[1] Configure SMTP Server in order to scan emails to protect from virus or spams. Install clamav first.
# install from DAG

[root@mail ~]#
yum --enablerepo=dag -y install clamd amavisd-new


[root@mail ~]#
vi /etc/clamd.conf


# line 72: change

LocalSocket
/var/run/clamav/clamd.sock


# line 80: make it comment

#
TCPSocket 3310

# line 149: change

AllowSupplementaryGroups
yes


[root@mail ~]#
vi /etc/amavisd.conf


# line 20: specify domain name

$mydomain
= '
server.world
';


# line 80: make it comment (not notify if virus detected)

#
$virus_admin
= "virusalert\@$mydomain";


# line 113: uncomment and specify FQDN

$myhostname
= '
mail.server.world
';


# line 115,116: uncomment

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

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


# line 118: uncomment thease 4 lines

$final_virus_destiny
= D_DISCARD;

$final_banned_destiny
= D_BOUNCE;

$final_spam_destiny
= D_BOUNCE;

$final_bad_header_destiny
= D_PASS;


# line 321: uncomment thease 4 lines

['ClamAV-clamd',
  &ask_daemon, ["CONTSCAN {}\n", "/var/run/clamav/clamd
.sock
"],
  qr/\bOK$/, qr/\bFOUND$/,
  qr/^.*?: (?!Infected Archive)(.*) FOUND$/ ],

[root@mail ~]#
vi /etc/postfix/main.cf


# add at the bottom

content_filter=smtp-amavis:[127.0.0.1]:10024


[root@mail ~]#
vi /etc/postfix/master.cf


# add at the bottom

smtp-amavis unix -       -       n      -     2 smtp
      -o smtp_data_done_timeout=1200
      -o smtp_send_xforward_command=yes
      -o disable_dns_lookups=yes
127.0.0.1:10025 inet n     -     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 smtpd_error_sleep_time=0
      -o smtpd_soft_error_limit=1001
      -o smtpd_hard_error_limit=1000


[root@mail ~]#
/etc/rc.d/init.d/clamd start

Stopping Clam AntiVirus Daemon:
[ OK ]

Starting Clam AntiVirus Daemon: Running as user clamav (UID 100, GID 101)   [ OK ]
[root@mail ~]#
/etc/rc.d/init.d/amavisd start

Starting Mail Virus Scanner (amavisd):
[ OK ]

[root@mail ~]#
/etc/rc.d/init.d/spamassassin start

Starting spamd:
[ OK ]

[root@mail ~]#
/etc/rc.d/init.d/postfix restart

Shutting down postfix:
[ OK ]

Starting postfix:
[ OK ]

[root@mail ~]#
chkconfig amavisd on

[root@mail ~]#
chkconfig spamassassin on

[root@mail ~]#
chkconfig clamd on

  These lines below are added in header section of emails after this configuration.