Exchange not receiving e-mail after installing ISA 2004

I upgraded our Server from SBS 2003 Std. to 2003 Premium. Our previous setup was that everything went through a Pix firewall and from there into our switch.
Now I am using both NIC’s in the server and took off the Pix. I went from our router straight to the server and assigned the IP from the Pix to the server (so the public IP address has not changed). I installed ISA 2004 and no e-mail is coming in (outbound mail works fine). There is a SBS SMTP Access rule in the ISA that appears to route all SMTP traffic to the local host.
Our e-mail is first routed through McAfee servers for spam and antivirus filtering and all mail seems to be stuck there.

Thanks in advance for any advice on how to fix this.