In addition to introducing Collaboration Data Objects for Exchange Management (CDOEXM) in Exchange 2000 Server, Microsoft has introduced Collaboration Data Objects for Exchange 2000 Server (CDOEX) and Collaboration Data Objects Workflow Objects for Exchange (CDOWF). You must install and run CDOEX and CDOWF on an Exchange 2000 server. In other words, you can't install CDOEX and CDOWF on a separate computer and use that machine to manage your Exchange 2000 servers remotely.
CDOEX delivers a set of COM classes and interfaces that you can use to create and manage objects. Using CDOEX and ActiveX Data Objects (ADO), you can programmatically manage most types of items in the Microsoft Web Storage System (WSS). ADO lets you navigate through the WSS; CDOEX lets you understand the purpose of the various types of items in the WSS.
CDOEX objects are described (and programmed) in terms of the interfaces they implement and the properties, methods, and collections that those interfaces provide. You use properties to set and read information about the object, whereas you use methods to perform an action. For example, consider the Message object, which represents a message in Exchange 2000. Through the object's IMessage interface, you use the To property to set the message's recipients. After you've set all the mandatory properties, you use the Send method to send the message.
CDOWF delivers a set of COM classes and interfaces that let you manage Exchange 2000 workflow processes. Exchange 2000's Workflow Engine determines the state of an item based on an action table defined within a process-definition item. This process-definition item defines the conditions under which a state should change and the actions to perform when a state changes. CDOWF lets you programmatically manage process-definition items and associated components. For example, you can programmatically query the AuditTrail property, which shows you the states and actions through which that the item has already passed. (For more information about CDOWF, see the Windows 2000 Magazine article "Exchange 2000 Workflow Applications," February 2001.)