Java

new Thread(new Runnable(){
    public void run(){
        // invoke native function
    }
}).start();

public class Program
{
    public static void main(String[] args)
    {
        try
        {
            // Check arguments
            if (args.length != 3)
            {
                ShowUsage();
                return;
            }
            // Create message
            MailMessage mmMessage = new MailMessage();
            mmMessage.To.add(new MailAddress((String)((args[2] instanceof String) ? args[2] : null)));
            mmMessage.From = new MailAddress((String)((args[1] instanceof String) ? args[1] : null));
            mmMessage.Subject = "TestMail";
            mmMessage.Body = "This is a test";
            // Send message
            SmtpClient sc = new SmtpClient((String)((args[0] instanceof String) ? args[0] : null));
            sc.Send(mmMessage);
        }
        catch (Throwable ex)
        {
            System.out.println(ex);
        }
        finally
        {
            //Pause
            System.out.println();
            System.out.print("Press a key >");
            Console.ReadKey();
        }
    }
    private static void ShowUsage()
    {
        System.out.println("Usage");
        System.out.println("TestMail [SmtpServer] [FromAddress] [ToAddress]");
    }
} // end Program

exec(String command, String[] envp, File dir)