Create the internal mime header, as found on the mime-attachment itself.
[Visual Basic] Protected Function GetInternalMimeHeader( _ ByVal encoder As IEncoder _ ) As String [C#] protected string GetInternalMimeHeader( IEncoder encoder ); [C++] protected: String* GetInternalMimeHeader( IEncoder* encoder ); [JScript] protected function GetInternalMimeHeader( IEncoder encoder ): String;