One of the largest issues with email today is the problem of Unsolicited Bulk Email (UBE). Also known as SPAM, such messages may also carry viruses and other forms of malware. According to some reports these messages make up the bulk of all email traffic on the Internet.

To install the rest of the applications enter the following from a terminal prompt:

sudo apt-get install amavisd-new spamassassin clamav-daemon sudo apt-get install dkim-filter python-policyd-spf

There are some optional packages that integrate with Spamassassin for better spam detection:

sudo apt-get install pyzor razor

Along with the main filtering applications compression utilities are needed to process some email attachments:

sudo apt-get install arj cabextract cpio lha nomarch pax rar unrar unzip unzoo zip zoo

Configuration

Now configure everything to work together and filter email.

ClamAV

The default behaviour of ClamAV will fit our needs. For more ClamAV configuration options, check the configuration files in/etc/clamav.

Add the amavis user to the clamav group in order for Amavisd-new to have the appropriate access to scan files:

sudo adduser amavis clamav

Thanks to http://techgurulive.com/2009/01/13/how-to-install-and-configure-clamav-on-ubuntu/