Mail server with ASSP - Question

[AkumA]

About this: http://www.howtoforge.com/antispam_smtp_proxy

i haven't understand one thing.
I have an Ubuntu 6.06.1 LTS Server 64Bit edition and i want to make it a Mail Server with antispam in front of a Exchange server.

Starting reading the HowTo i haven't understood if i have to setup enterely my server with postfix together with ClamAV+SpamAssassin+etc

Right now i'm following this one:
http://www.howtoforge.com/postfix_antispam_mailscanner_clamav_ubuntu

Have i to complete this howto and THEN use the ASSP howto, or i need just a simple installation of PostFix and related packages and than start immediatly with ASSP's howto?
And, if i need a simple installation, could you please tell me where i have to stop?

Thank you

[falko]

I think you need a simple installation as everything else would be overkill. Something like the Postfix setup on http://www.howtoforge.com/perfect_setup_debian_sarge , for example.

[AkumA]

mmm.. yeah, it looks like the Ubuntu's one. Thanks!
any one that maybe can "handle" better my problem?

[AkumA]

What if i have to put this server in a lan where clients receive their mails through a pop directly (Like a normal user could do with his own provider using Outlook or something like that)?

Thanks

[falko]

You could let your mail server fetch the mails from POP3 with fetchmail, then scan them for spam, and then make the email clients fetch the mails from your mail server instead of from the mail server of the ISP.

Otherwise, if your users fetch their mails directly from their ISP's mail server, then there's no point in setting up your own mail server.

[AkumA]

Thank you so much :)

In this case the provider gives webmail and a mail.provider.com as a pop3 to setup into OutLook.