AntiSpam and Antivirus with Postfix/Courier Mailserver

We have a mail server which provides us with an anti-spam service. We need to upgrade our server to be more up-to-date to prevent the latest types of spam. We will provide access to a clean virtual server, where you will need to install a mailserver (based on our specifications) and install a system to block spam. We will provide you with a description of our current anti-spam setup. You can choose to update this system, or install a different type of anti-spam whichever you think is best. ## Deliverables Specification of our current mail server (with outdated anti spam): sistema operativo ubuntu 5.10 servidor smtp con postfix 2.2.4 servidor imap: courier version 3.0.8-3 autentificacion open-ldap amavis 0.1.6.9-1 antivirus clamav 0.87-1 antivirus pyzor 0.4.0 razor 2.720 spamassassin 3.0.4-2 This is our current setup. You are free to suggest other means for antivirus and antispam. Required solution is a solution based on Ubuntu Server 9.04. This will be the operating system of the virtual server to which we will provide access.