This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.
Spam is an unwelcome e-mail message from a business or individual (sometimes sent from a nonexistent user or domain) that seeks to sell the recipient something. Spam may also be spoofed to appear to originate from an internal user.
The Microsoft® Exchange Server 2003 anti-spam infrastructure takes advantage of the SMTP service that ships in the Microsoft Windows® 2000 and Microsoft Windows Server 2003 operating systems. The SMTP service provides an event architecture that allows custom extensions of the core RFC 2821 protocol. For more information about this architecture, see the Microsoft Windows 2000 SMTP Service Events white paper and the SMTP Server Events documentation on MSDN®.
The sections below further describe the Exchange Server 2003 anti-spam infrastructure and how to implement and extend an SMTP protocol event sink to address spam as it enters the organization at the gateway.
The Anti-Spam Infrastructure section describes the anti-spam infrastructure in Exchange Server 2003 and discusses how the protocol sink template and your custom spam filter fit into this structure.
The Spam Filter section discusses the functionality your spam filter should include, as well as what the spam confidence level (SCL) is and how your filter should use the SCL value.
The Administration section contains information about the settings you will need to set on the content filter object.
The Configuration section illustrates how to create the content filter object and discusses the data held by that object.
The Protocol Sink Template section describes the sample protocol sink template, the code files included, and how to extend and build the template.