Postfix and Smart Host / Relay Host

[SuperHack]

Help Please.. Postfix Gods.

Situation

I have 2 offices (1) Central office with a mail server running on a static IP hosting the companies email server using Mandrake Linux and Postfix server chroot setup. To make things more fun I added in some additional requirements to help prevent people from using us as a spam sender. So I added a check mail request prior to sending email, this was fine and dandy when I was able to just use outlook, but now I need to add additional location that needs to use the central email server as its relay b.c the new location is on the cheap cheap and using a dynamic IP wich .. well almost everything is bounced back.

Ex: Domains

central mail server - mail.mainbase.net

2nd site - mail.techbase.net

So I need to setup my postfix config to use a smart host but I need it to check for email first, then if auth is succesful send mail out.

mail.techbase.net relays to mail.mainbase.net

I tried enabling SASL Auth on techbase.net but when it connects I get No AUTH Mechanisms found. I am thinking this is b/c its chroot but I am not sure how to make them found or if I am even loooking in the right direction.

Well if you can help please.