Per auditor recommend the Exhange (2003) front-end server with OWA & RPC over https should setup URLscan. After i setup the URLscan, all clients cannotusing RPC over http to connect Mailboxes. May i know this issues still on Exchange 2007. if Exchange 2007 can work with URLscan, i would recommend my boss t0 upgrade.
1. Exchange 2003 with URLscan issues should be related the URLscan setting. Please refer to below KB to fine tune. http://support.microsoft.com/kb/823175
2. We recommend that you do not run URLScan with IIS version 6.0 or IIS version 7.0 because the risk of misconfiguration is much more than the benefit that URLScan provides. http://technet.microsoft.com/en-us/library/bb691338.aspx