CDO 1.2 is a scripting-object library that developers can use to design collaborative applications on both the client and server side. It’s an in-process, self-registered COM server and is language-independent, compatible with Microsoft® Visual Basic® Scripting Edition (VBScript), ECMAScript, Java, C/C ++, Visual Basic, Visual Basic for Applications, and other languages. CDO 1.2 is also 100 percent compatible with existing applications developed against Active Messaging 1.1.
CDO 1.2 is tuned for a highly scalable, high-performance server environment. It is thread-safe, it supports multiple code pages for applications that require multiple languages, and it supports roughly 1,000 concurrent users per server. Also like Exchange 5.5, CDO 1.2 supports caching, which helps make it two to three times faster than Active Messaging 1.1.
For performance reasons, rather than having its own user interface, CDO 1.2 is accessed through Exchange 5.5. This means CDO 1.2 does not display its own dialog boxes, logon screen, or error messages.
CDO 1.2 is organized as a logon session consisting of two primary collections of objects: InfoStores and AddressLists. Under each, there are other objects, collections of objects, properties, and methods.
CDO 1.2 is used for streamlining the design of client applications, Web applications, and Exchange-server applications such as mailbox agents and server-event scripts, design-time controls, ActiveX™ run-time controls, and others. On the client side, for example, developers have used CDO 1.2 in the design of Microsoft Outlook™ Web Access. On the server side, developers are using it for mailbox agents, which
Microsoft Exchange Introduction to Collaboration Data Objects White Paper1