Postfix (Mail Relay) - Amavisd-new - Spamassassin - ClamAV

Thanks to these great opensource softwares, one can create a reliable anti-spam and anti-virus filter server.

I plan to create a Howto or Documentation to help others implement this on their system. This includes the iptables rules that are necessary and settings for using postfix as a mail relay to another secure server.

A quick run-through:
1) Install postfix (mail server)
- no restrictions yet
- just make sure everything is working properly as a mail relay

2) Install clamav (antivirus scanner)
- independent tests can be performed

3) Install spamassassin (antispam scanner)
- this is a simple process that testing can wait for amavisd-new

4) Install amavisd-new (makes all of them work harmoniously)
- this has a lot of perl module dependencies
- after the dependencies, installation is quite simple
- configuration will take some trial and error tests to suit your needs

Hopefully by December I would have finished the howto.