Chapter 13. Transport-Level Security

IN THIS CHAPTER

• The Onion Approach

• Using Public Key Infrastructure with Exchange Server 2003

• Supporting S/MIME

• Protecting Communications with IP Security

• Configuring IPSec

• Locking Down SMTP

• Securing Routing Group Connectors

• Securing Other Exchange-Supported Protocols

• Protecting Client–to–Front-end–Server Communications

• Locking Down Front-end and Back-end Server Communications

• Best Practices

Organizations of all sizes use Exchange Server 2003, not as simply an email system, but also for internal and external communications. This communication is vital to any organization and it must be efficient and secure. The level of security depends on the business, security policies, type and content of information being communicated, and which parties are communicating.

Securing external communication is vital—especially information that is transmitted over public networks such as the Internet. External communication is an important facet to address when considering transport-level security, but it is not the only important aspect to secure. Internal communication, whether it is internal employees sending messages or server-to-server interactions, are equally important. This chapter focuses on the mechanisms that exist to protect and encrypt information sent between computers on a network. New and improved transport security features in Windows Server 2003 and Exchange Server 2003 are examined.