OpenObjectメソッドを活用したサンプルコード集

https://docs.microsoft.com/en-us/previous-versions/exchange-server/exchange-10/ms526988(v=exchg.10)

' Reference to Microsoft ActiveX Data Objects 2.5 Library
' Reference to Microsoft CDO for Windows 2000 Library
Function LoadMessageFromFile(Path As String) As Message
    Dim Stm As New Stream
    Stm.Open
    Stm.LoadFromFile Path
    Dim iMsg As New CDO.Message
    Dim iDsrc As IDataSource
    Set iDsrc = iMsg
    iDsrc.OpenObject Stm, "_Stream"
    Set LoadMessageFromFile = iMsg
End Function

Function ExtractMessage(iBp As IBodyPart) As Message
    Dim iMsg As New CDO.Message
    Dim iDsrc As IDataSource
    Set iDsrc = iMsg
    iDsrc.OpenObject iBp, "IBodyPart"
    Set ExtractMessage = iMsg
End Function

Sub EmbedMessage(iMsg As CDO.Message, iBp As IBodyPart)
    Dim iDsrc
    Set iDsrc = iMsg.DataSource
    iDsrc.SaveToObject iBp, "IBodyPart"
End Sub