MailScanner + MailWatch integration in Debian Squeeze with Postfix and Courier

[johjoh2k]

Hello, would be great an howto for install MailScanner + MailWatch in Debian Squeeze.
I have read a lot, and:
- mailscanner are installable via aptitude http://packages.debian.org/mailscanner
- mailwatch are downloadable here http://mailwatch.sourceforge.net

What I' dont know is the mechanism of processing email when it arrive to Postfix, for scan for virus and spam.
My reality it's a multiserver setup, and my server email it's with Postfix, Courier, Roundcube, ClamAV, SpamAssassin and ISPconfig.
I want understand what I have to dismantle between Postfix-ClamAV-SpamAssassin for make email flow through MailScanner correctly

Obviously, after that I want that the site MailWatch work perfectly

Thank you if anyone would write it