The purpose of this installation is to filter spam email and virus on Postfix mail agent. Here I already installed Postfix in the server, because it is included in EHCP installation.
1. Install the packages
$ sudo apt-get install amavisd-new spamassassin clamav-daemon
2. Install the optional packages for better spam detection
$ sudo apt-get install libnet-dns-perl libmail-spf-perl pyzor razor
libmail-spf-query-perl package is not available in Debian, therefore I change to libmail-spf-perl.
3. Install these optional packages to enable better scanning of attached archive files
$ sudo apt-get install arj bzip2 cabextract cpio file gzip lha nomarch pax rar unrar unzip zip
I remove zoo and unzoo from the command line packages because Debian can’t find the source.
4. ClamAV configuration
Add clamav user to the amavis group and vice versa in order for ClamAv to have access to scan files.
$ sudo adduser clamav amavis $ sudo adduser amavis clamav
5. Spamassassin configuration
Edit /etc/default/spamassassin to activate the Spamassassin daemon.
$ sudo nano /etc/default/spamassassin
Find the lines ENABLED=0 and CRON=0, and update to the following:
ENABLED=1 CRON=1
Start spamassassin:
$ sudo /etc/init.d/spamassassin start
6. Amavis configuration
Activate spam and antivirus detection in Amavis by editing /etc/amavis/conf.d/15-content_filter_mode.
$ sudo nano /etc/amavis/conf.d/15-content_filter_mode
Uncomment the following lines:
@bypass_virus_checks_maps = ( \%bypass_virus_checks, \@bypass_virus_checks_acl, \$bypass_virus_checks_re); @bypass_spam_checks_maps = ( \%bypass_spam_checks, \@bypass_spam_checks_acl, \$bypass_spam_checks_re);
Restart Amavis:
$ sudo /etc/init.d/amavis restart
7. Postfix integration
Edit configuration file /etc/postfix/main.cf:
$ sudo nano /etc/postfix/main.cf
Add this line into the file:
content_filter = smtp-amavis:[127.0.0.1]:10024
Edit /etc/postfix/master.cf
$ sudo nano /etc/postfix/master.cf
and add the following lines to the end of the file: (add 3 blank spaces in front of ‘-0’)
smtp-amavis unix - - - - 2 smtp -o smtp_data_done_timeout=1200 -o smtp_send_xforward_command=yes -o disable_dns_lookups=yes -o max_use=20 127.0.0.1:10025 inet n - - - - smtpd -o content_filter= -o local_recipient_maps= -o relay_recipient_maps= -o smtpd_restriction_classes= -o smtpd_delay_reject=no -o smtpd_client_restrictions=permit_mynetworks,reject -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o smtpd_data_restrictions=reject_unauth_pipelining -o smtpd_end_of_data_restrictions= -o mynetworks=127.0.0.0/8 -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000 -o smtpd_client_connection_count_limit=0 -o smtpd_client_connection_rate_limit=0 -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks
Find pickup line (Ctrl-W in nano), and add these lines below the pickup line: (add 3 blank spaces in front of ‘-0’)
-o content_filter= -o receive_override_options=no_header_body_checks
This will prevent messages that are generated to report on spam from being classified as spam.
Reload Postfix:
$ sudo /etc/init.d/postfix reload
Restart ClamAv:
$ sudo /etc/init.d/clamav-daemon restart
8. Test Amavis
$ telnet localhost 10024 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 [127.0.0.1] ESMTP amavisd-new service ready
Press Ctrl-] to exit.
9. Check on your /var/log/mail.log that everything goes well. If you see an error message similar to the following:
amavis[30807]: (30807-01) (!!) ask_av (ClamAV-clamd) FAILED – unexpected result: /var/lib/amavis/tmp/amavis-20070615T125025-30807/parts: lstat() failed. ERROR\n
fix it by restart all the services:
$ sudo /etc/init.d/postfix restart $ sudo /etc/init.d/spamassassin restart $ sudo /etc/init.d/clamav-daemon restart $ sudo /etc/init.d/amavis restart
10. Done
