public static void Convert(String htmlFilename, String mhtFilename)
{
var objMessage = new Message();
objMessage.CreateMHTMLBody(htmlFilename);
var strm = new Stream {Type = StreamTypeEnum.adTypeText, Charset = "US-ASCII"};
strm.Open();
IDataSource dsk = objMessage.DataSource;
dsk.SaveToObject(strm, "_Stream");
strm.SaveToFile(mhtFilename, SaveOptionsEnum.adSaveCreateOverWrite);
strm.Close();
}