KB: Suitable Applications for Exchange Server Event Scripting

The following article details some of the limitations of Exchange Server Event Scripting (available in Exchange 5.5). With the availability of Exchange Event Sinks in Exchange 2000/2003 it is really hard to rationalize continued use of this technology. Especially for mission critical applications...

181036 INFO: Suitable Applications for Exchange Server Event Scripting

Most notable from this article are the following...

"There is no guarantee that a script will see every message."

"The Event Service is single-threaded. No matter how many scripts are registered, only one can run at a time."

"The Scripting Agent is not a safe, general purpose replacement for the Inbox Assistant rules because it allows new code to be installed and run on your servers."

One major consideration between Event Scripts and Event Sinks is that Scripts use CDO 1.21 as their API while Sinks use CDOEX. It is often suprising have minor the code changes can be for simple script migration. CDOEX is a better performing and more robust API, adding to the list of reasons to make the switch.

...NOTE: This is what I refer to as Event Scripts in this article...


...You can create Exchange Event Sinks using VBScript, these scripts wouldn't have the limitations listed above. The KB article below provides a sample event sink script...


Updated 1/22/2009 – Noted a broken link.