You can now download the MAPI subsystem and CDO 1.21 from Microsoft and install them separate from Exchange or Outlook.  This is a totally standalone download that is comprised from the Exchange 2003 build tree and is fully supported.  Here is the download link…

 

Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1

http://www.microsoft.com/downloads/details.aspx?familyid=E17E7F31-079A-43A9-BFF2-0A110307611E&displaylang=en

 

…This is a significant change in that application servers that need MAPI or CDO 1.21 don’t need to have Exchange, Outlook, or Exchange System Manager installed; just this package.  This is the Exchange version of MAPI and CDO with the same benefits and pitfalls, e.g. there are no security dialogs in CDO and there is no Unicode support...

 

…This package will not install on a machine with Outlook and Exchange.  The installer actually protects you from making this mistake…

 

…Stephen Griffin has more on the download…

 

Updated 3-16-07: I just ran across some details in the readme.txt file that is installed with this download.  We have had a couple customers who were unsure what exactly this MSI installs.  Here is the file list from the readme file...

 

" This release includes installers for MAPI32.DLL, the associated providers, and CDO 1.2.1. Specifically, it installs the following features:

 

* MAPI32.DLL, CDO.dll
* Exchange store provider: EMSMDB.DLL
* Exchange address book provider: EMSABP.DLL
* Exchange PST provider: MSPST.DLL
* MAPI spooler: MAPISP.dll "