DMZ Guest Wireless access to Exchange OWA Issue

[jahicks7]

I am using a FortiWiFi 90D and have my internal network set up on Interface 14 using WAN1. It is configured and passing traffic perfectly using a Public IP of 1XX.XX.XX.13. The Firewall is also set up to pass certain ports on the public ip 1XX.XX.XX.10 to the Internal Exchange Server on Interface 14 via WAN1. That is working fine as well.

I am trying to create a DMZ for a Guest WIFI Setup on Interface 3 and WAN1 using a Netgear Wireless router internally. I need to be able to connect to the Guest wireless and open the Exchange OWA Web Interface without the guest network having access to my entire internal network..

The guest WIFI Interface works fine except for accessing the Exchange OWA Web Interface via the public ip.  It is able to resolve the Public IP of the Exchange Server to the correct IP Address 1XX.XX.XX.10, but cannot open the Web Mail (OWA) interface. Any Suggestions?

Thanks

Jeff