In order to execute the following steps, you will need to have a server running UAG 2010 Service Pack 3. The server needs to be Internet connected and have at least two network adapters: one connected to the internal network and to the perimeter network.

Furthermore, we assume that you already installed the Exchange certificate onto the server and that you configured an authentication server using the Authentication and Authorization Servers... wizard from the Admin menu.

Although Service Pack 3 for UAG 2010 officially added support for Exchange Server 2013, users will be presented with an Exchange 2010 Login-form for OWA. If this isn't something you want, you'll have to use another reverse-proxy solution.