Microsoft is committed to providing the ability to programmatically access Exchange 2000 Server by using the latest available .NET technologies. If you build a .NET Framework application, the supported options for accessing Exchange data are:
- WWW Distributed Authoring and Versioning (WebDAV) through HTTP requests and responses.
- Collaboration Data Objects (CDO) for Exchange 2000 Server (CDOEX) and Exchange OLE DB provider (ExOLEDB) through an interop assembly.
- Windows Management Instrumentation (WMI).
- Collaboration Data Objects for Exchange Management (CDOEXM).
For .NET Framework applications that send mail without using Exchange Server as the transport, Microsoft CDO for Windows 2000 (CDOSYS) can be used through an interop assembly. However, Microsoft recommends using System.Web.Mail. System.Web.Mail is a managed wrapper to CDOSYS that enables you to construct and send messages by using the CDOSYS message component. The mail message is delivered either through the SMTP mail service that is built into Microsoft Windows 2000 or through an arbitrary SMTP server.
CDO 1.2x and MAPI are not supported in a .NET Framework environment. For CDO 1.2x and MAPI type functionality, use one of the supported access methods mentioned in the "Summary" section.
For .NET Framework applications that must send mail without using Exchange Server as the transport, System.Web.Mail is a good option. However, Microsoft Collaboration CDOSYS can also be used through an interop assembly.
CDO 1.2x and MAPI are not supported in a .NET Framework environment.
The following table summarizes the support policy for Exchange APIs in a .NET environment:
|API||DLL Name||Managed Code Support Policy|
|CDOSYS||CDOSYS.DLL||Supported, but System.Web.Mail is recommended|
|CDOEXM||CDOEXM.DLL||Supported by using a COM interop assembly|
|EXOLEDB||Supported by using a COM interop assembly|
|CDOEX||CDOEX.DLL||Supported by using a COM interop assembly|
|CDO 1.2x||CDO.DLL||Not Supported|
|ESE Backup API||ESEBCLI2.DLL||Not Supported|
.NET Interop: Get Ready for Microsoft .NET by Using Wrappers to Interact with COM-based Applications
Introduction to COM Interop
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Advanced COM Interop
Handling COM Interop Exceptions
Article ID: 813349 - Last Review: Jun 5, 2008 - Revision: 1