Now, there are no official binary PIAs for Exchange Server 2000 / 2003. However, Microsoft does provide such PIAs in "source" form (not really source code as such... but we'll get to that) that you can download and compile yourself. There is an MSDN article that explains how to use the Exchange Server PIA wrappers, however I strongly recommend you download the code and read the included "Writing Managed Sinks for SMTP and Transport Events.doc" file instead - it is far more up to date than the MSDN article in areas that are quite significant (such as the actual build process).