Knowledge Base Article 838454 describes the new Microsoft.BizTalk.MessageBoxOM.MessageArchive object that was added to Microsoft.BizTalk.MessageBoxOM.dll. Currently, the package is only available through Microsoft Support.
There are a few things that this KB Article does not describe: remember that the Microsoft.BizTalk.MessageBoxOM.dll file is in the GAC. Currently, Visual Studio.NET 2003 does not allow you to add references to components in the GAC. To get past this, you can choose one alternative between these two solutions:
1 - Extract the dll from the GAC to a place where you can add reference to it (perhaps C:\<yourprojectdirectory>)
In a DOS prompt, run the following command:
copy %systemroot%\assembly\GAC\Microsoft.BizTalk.MessageBoxOM\126.96.36.199__31bf3856ad364e35\Microsoft.BizTalk.MessageBoxOM.dll <destination_path>
Where <destination_path> has been replaced by the path to your BizTalk project's directory (for instance C:\MyProject)
2 - Manually edit the Visual Studio Project file (.csproj, .btsproj, .etc)
To add a reference to this assembly you must edit the project file (.csproj, .btproj, .etc) in a text editor. The following code snippet shows the code that must be added to the reference element of the project file to reference the assembly:
Name = "Microsoft.BizTalk.MessageBoxOM"
AssemblyName = "Microsoft.BizTalk.MessageBoxOM"
HintPath = "<SystemRoot>\assembly\GAC\Microsoft.BizTalk.MessageBoxOM\188.8.131.52__31bf3856ad364e35\Microsoft.BizTalk.MessageBoxOM.dll"