Exchange Server 2003 provides a great range of remote connection and management features. However, there are many attacks and automated scripts in the hands of attackers that attempt to compromise Exchange servers. Outlook Web Access provides an easy-to-configure way to allow your users remote access to their e-mail, but significant security issues can compromise the integrity of your network. When you absolutely need to provide full access for Outlook clients, you must do so in a secure fashion.
This chapter highlights the security issues involved with providing Outlook Web Access or full Outlook client connections over the Internet, and then discusses how ISA Server 2004 can be configured to mitigate these threats. We start with Outlook Web Access as the simplest solution.