Can't find Postfix documentation for a specific configuration.
 

I have been tasked with creating a Postfix mail server.

The client has a web host that actually hosts their domain (for the sake of reference I will refer to it as theirdomain.com.) It handles all pop3 services for them. They also have a couple of accounts that check their box via webmail services.

They want me to configure a box for them using Postfix and SpamAssasin or DSPAM.

The web host has their mail boxes set up so that all mail not specifically forwarded to a box goes to the master account (master@theirdomain.com) The way the host recommends I go about this is to delete all of the non webmail accounts on their server so that it all goes to the master account, then have Postfix connect and download the messages for the master account and parse them out to the individual boxes from there.

One more caveat...this is a corporate mail system and their email can suffer very little if any downtime...

:scratch:
The problem I am running into is finding any Postfix Documentation on how to do that or something even remotely similar. Does anyone know where I should look? If it is simple enough to post here, does anyone know how to do this very thing? Postfix is already installed so I have that base covered. I just need to know how to configure it to do what they want. Thanks in advance for any help