CDOWF Evaluation Criteria

Topic Last Modified: 2008-09-02

CDO for Workflow (CDOWF) is built-in functionality provided with Microsoft Exchange 2000 Server. By using CDOWF, which is driven by the Exchange store event architecture, you can design workflow applications without having to write the fundamental code that accesses, modifies, and controls data. CDOWF includes a workflow engine, modeling tools, and an event sink.


CDOWF does not ship in and is not supported for Microsoft Exchange Server 2007. Use the Windows Workflow Foundation (WWF) to create applications that use workflow and orchestration.


Consider using Microsoft BizTalk for more complex workflow process implementations, especially those that require more complex workflow processing, must cross organizational boundaries, or are not messaging-related.

Functional Criteria

Criteria Collaboration Data Objects for Exchange Workflow (CDOWF)

Application Domain

CDOWF is used within workflow processing systems, enabling them to define and control workflow processes, and to respond to workflow events that are part of those processes.

Major Objects

CDOWF provides COM/Automation-compatible objects that support workflow processes. These include ProcessDefinition, ProcessInstance, and WorkflowSession. Custom events used in workflow processes are implemented by using the Exchange store events interfaces.

Data access model

Mixed: Collections of some object types can be accessed as ADO rowsets by using the DataSource object. Other CDOWF items are presented as hierarchical objects.

Threading Models

No specific threading prohibitions. However, applications that use free-threading should never share CDOWF object instances among asynchronously operating threads. Multithreading should not be used within workflow events.

Application Architectures

Typical uses are for applications that implement messaging-related business processes.

Remote Usage

CDOWF can only be run on the Exchange 2000 Server or Exchange Server 2003.


Transactions can be implemented as part of the overall workflow process, but CDOWF does not natively support transactions.

Management Capabilities

CDOWF does not generate standard Windows Event Log entries. CDOWF does provide the ability to log workflow process events in special audit logs that are maintained by the process instances of the CDOWF system.


Shipped with Exchange 2000 Server and Exchange Server 2003. CDOWF does not ship with and is not supported for Exchange 2007. CDOWF is expected to be enhanced or replaced in a future version of Exchange. Consider using Microsoft BizTalk for more complicated, inter-organizational, and non-messaging related workflow process implementations.

Development Criteria

Criteria Collaboration Data Objects for Exchange Workflow (CDOWF)

Languages and Tools

CDOWF can be used with any COM/Automation-compatible language, as well as with non-COM languages such as C/C++.

Managed Implementation

CDOWF is an unmanaged component. Use of CDOWF is not supported under the COM Interoperability layer of Visual Studio .NET.


CDOWF is scriptable by means of ASP and Windows Scripting Host. However, this scenario is rather unusual, because applications that define workflow processes are usually larger and more complex than is appropriate for a script-based application.

Test/Debug Tools

No special debugging tools are needed to debug applications that use CDOWF. Custom applications might be created to analyze the process audit logs created during process execution. If you are using the Workflow Designer for Exchange 2000 Server, enable Just-In-Time (JIT) script debugging. JIT starts the Microsoft Script Debugger when the error occurs. The debugger starts on the server, so you need to have access to the server.

Expert Availability

Relatively few people are considered experts at programming CDOWF; finding trained experts might be difficult.

Available Information

Some Microsoft and third-party books describe CDOWF. In addition, CDOWF is documented in the Exchange 2000 Server SDK and the Exchange Server 2003 SDK. Use the documentation appropriate to the version of Exchange for which you are developing. To access the Exchange 2000 Server and Exchange Server 2003 SDKs, see the Exchange Server Developer Center.

Developer/Deployment Licensing

Refer to your Exchange and MSDN subscription licensing agreements to determine whether additional licenses are required for the computers where your CDOEX applications are developed and deployed.

Security Criteria

Criteria Collaboration Data Objects for Exchange Workflow (CDOWF)

Design-Time Permissions

The developer or workflow process designer must have permissions to access the mailboxes and folders used by the workflow process. Read the appropriate section of the Exchange SDK for more information about permissions required with workflow processes.

Setup Permissions

Applications that use CDOWF are stored on the Exchange server. Direct access to that server, however, is not required. The Workflow Designer can be used to deploy workflow applications remotely on an Exchange server, with the requirement that the user have sufficient permissions to access the mailboxes where the application is to be installed.

Run-Time Permissions

Workflow processes created by applications that use CDOWF are run under the Workflow System Account. That account needs access to the folders and other resources for use by the workflow processing and code. Read the appropriate SDK for more information about permissions required for workflow processes.

Built-in Security Features

Workflow processes always run as the Workflow System Account. Workflow events can log entries in the workflow audit log.

Security Monitoring Features

Workflow events can log entries in the workflow audit log.

Deployment Criteria

Criteria Collaboration Data Objects for Exchange Workflow (CDOWF)

Server Platform Requirements

CDOWF can only be run on a computer that is running Exchange 2000 or Exchange 2003.

Client Platform Requirements

Workflows can be designed on any computer on which the Workflow Designer for Exchange is installed. The Workflow Designer is no longer available for download. Application clients that directly access CDOWF must be installed and must run on an Exchange Server 2000 or Exchange 2003 Server.

Deployment Methods

If the client or application that is being installed needs direct access to CDOWF, the installer should verify that the computer is an Exchange 2000 or Exchange 2003 server, and that CDOWF is correctly installed on the computer.

Deployment Notes