Redirection to OWA 2007 Directory in ISA 2004/2006
Introduction
Recently I have seen a fair number of cases where ISA Administrators were trying to redirect connections made to the root OWA Web site to the /owa folder when publishing Exchange 2007 through ISA Server 2004/2006. In these particular cases they were using a documented trick for Exchange 2003 that involves entering a path on the OWA rule that looks like this /exchange\ . The trick is documented here and works quite well for Exchange 2003. The problem is that people believe it should also work for Exchange 2007. When they try this method they end up with a garbled inbox with a lot of red Xs showing up as shown in Figure 1: See more at the SOURCE
Source: Forefront TMG (ISA Server) Product Team Blog : Redirection to OWA 2007 Directory in ISA 2004/2006