Can't send mail with html in the body

public class Main {
         public static void main(String[] args) {  
       
             ActiveXComponent oOutlook = new ActiveXComponent("Outlook.Application");  
             Dispatch.call(oOutlook ,"GetNamespace","MAPI").toDispatch();
             Dispatch email = Dispatch.invoke(oOutlook.getObject(),"CreateItem", Dispatch.Get, new Object[] { "0" }, new int[0]).toDispatch();  
             Dispatch.put(email, "To", destinatario);  
             Dispatch.put(email, "Subject", asunto);  
             Dispatch.put(email, "Body", cuerpoMensaje);  
             Dispatch.put(email, "Body", getCuerpoEmail("C:\\archivo.html"));
             Dispatch.put(email, "ReadReceiptRequested", "false"); 
             try {  
                 Dispatch.call(email, "Send");  
             } catch (com.jacob.com.ComFailException e) {  
                 e.printStackTrace();  
             }  
    }
         public static String getCuerpoEmail(String fileName)
        {
            String message = null;
            FileInputStream file;
            try {
                file = new FileInputStream(fileName);
                byte[] b = new byte[file.available()];
                file.read(b);
                file.close();
                message = new String(b);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return message;
        }
}