msg = new CDO.MessageClass();
ADODB.Stream stream = new ADODB.StreamClass();
stream.Open(Type.Missing, ADODB.ConnectModeEnum.adModeUnknown, ADODB.StreamOpenOptionsEnum.adOpenStreamUnspecified, String.Empty, String.Empty);
stream.LoadFromFile(emlFileName);
stream.Flush();
msg.DataSource.OpenObject(stream, "_Stream");
msg.DataSource.Save();
Its working fine for normal emails. But if HTML is embedded in email then it is giving "[Text Box: value ]" in the message body for the values that is entered in textbox.