The Microsoft® Exchange Server Scripting Agent lets you use server-side scripts that run as a result of events occurring in folders. Such triggering events include timer events and actions such as posting, editing, or deleting a message. They can take place in private folders (mailboxes) or public folders. You need sufficient folder permissions to install and enable event-driven folder scripts.
You can write these scripts in VBScript, JavaScript, or other supported scripting languages, and you can use Notepad (by default) or Microsoft Visual Studio (specifically, the Microsoft Developer Studio IDE) as your script editor, in conjunction with Microsoft Outlook version 8.03. See Writing and Installing Scripts.
Collaboration Data Objects (CDO, formerly Active Messaging) is the primary interface that scripts use to access and manipulate data in Microsoft Exchange information stores. (These scripts call CDO objects to perform their operations.) For more information, see Overview of Collaboration Data Objects.