How to forward e-mail to a new IP and receiving through Exchange 2003

We just moved to a new network and therefore have a new Exchange server and domain controller.  The company's old IT administrator forwarded e-mail from their Exchange server to our new's IP of 24.39.202.154 which is the static IP (public) that I gave him.  It is also the IP mapped to our internal IP of 192.168.20.3 (which is our server IP inside).   I'm not sure I configured Exchange and the Router correctly in order to start receiving mail because when I try to send from another domain it bounces back.  Here is the error:

Hi. This is the qmail-send program at totaltechsolution.com.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<RichardS@americaninvestment.com>:
205.231.144.69 does not like recipient.
Remote host said: 550 cuda_nsu 5.7.1 Unable to relay for RichardS@americaninvestment.com Giving up on 205.231.144.69.

--- Below this line is a copy of the message.

Return-Path: <Matthew.Patryn@totaltechsolution.com>
Received: (qmail 15415 invoked from network); 17 Mar 2008 12:10:05 -0000
Received: from unknown (HELO totaltechsolution.com) (195.24.53.55)
  by tts-gw.totaltechsolution.com (195.24.53.33) with ESMTP; 17 Mar 2008 12:10:05 -0000
Content-class: urn:content-classes:message

Any ideas, this is very important?  I think I setup Exchange 2003 correctly by allowing the relay of mail through the SMTP Virtual Server as well as granting permissions using that IP and all others.  I setup a Routing Group, and just used DNS to route mail.  Address space is configured to SMTP (Domain= americnainvestment.com).  

I added an mx.americaninvestment.com into the DNS records as well.  

What am I doing wrong?