A Good/Secure Reverse Proxy Product

[pguibord () thenailcogroup com]

Greetings to all,
 
We have a new MS Exchange server and the administrator wants to provide remote Outlook Web Access access to it from the 
internet.
As opposed to having a direct outside to inside translation to it I was told that we could put a reverse proxy server 
in the DMZ and then provide a DMZ to inside translation form there.
 
First of all does this sound like the safest approach and if so can anyone provide the name of a good stable/secure 
reverse proxy product.
 
Thanks,
 
Paul