How to write a SMTP event sink in C#

This document from MSDN gives a step-by-step guide for creating an event sink using C#.  Event sinks give you the power to change the way Exchange does things, allowing the server to react or to take action when specific events fire.


Here is the MSDN Article:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsmtps/html/writingmngsinks.asp

The YHMAEHLO link to the same article:
http://blogs.msdn.com/exchange/archive/2004/06/16/157550.aspx