This is actually a common question about Postfix. The answer is no, you
can't do anything within Postfix itself to make an inbound/outbound
distinction.
The best answer is apparently to run a separate postfix server on the
same box. The document on www.spamassassin.org about making Postfix work
On Fri, 2003-01-31 at 13:12, Ray Dzek wrote:
> I want to take the functionallity of the 3 boxes I have now (Inbound Postfix
> +SA, Sendmail Outbound Relay, and Postfix + POP3) and cut that all down to
> one box. The transport mappings and aliases required to get the Mac users
> onto the POP3 box
