Now that Exchange Server 2013 is available, some of you may well be wondering how to publish it to the Internet using Microsoft Threat Management Gateway (TMG) or perhaps the Microsoft Unified Access Gateway (UAG).

This post will help you configure TMG, for sure, but not UAG – as for the time being, you can’t effectively publish Exchange Server 2013 using UAG without turning off many of the security features in UAG. Why’s that? Well, as you’ll have gathered from other posts on this fine blog, we re-wrote OWA for Exchange 2013. And when an application like UAG inspects OWA traffic, it gets a little confused when you change everything, without telling it. So, the UAG team are busy beavering away re-writing their rule sets to work properly with Exchange 2013, so the advice for now if you have UAG, is to wait for a future UAG update, where it is currently expected that Exchange Server 2013 support will be added.

So back to TMG. TMG can be configured to work with Exchange Server 2013, and that’s what I’m going to walk through in this post. 

--> Please see the rest on the blog : http://blogs.technet.com/b/exchange/archive/2012/11/21/publishing-exchange-server-2013-using-tmg.aspx