I'm trying to work with the below code:

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import javax.mail.*;
import javax.mail.internet.*;   // important
import javax.mail.event.*;      // important
import java.net.*;
import java.util.*;

public class servletmail extends HttpServlet {
    public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();
        response.setContentType("text/html");
        try {
            Properties props=new Properties();
            props.put("mail.smtp.host","localhost");   //  'localhost' for testing
            Session   session1  =  Session.getDefaultInstance(props,null);
            String s1 = request.getParameter("text1"); //sender (from)
            String s2 = request.getParameter("text2");
            String s3 = request.getParameter("text3");
            String s4 = request.getParameter("area1");
            Message message =new MimeMessage(session1);
            message.setFrom(new InternetAddress(s1));
            message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(s2,false));
            message.setSubject(s3);
            message.setText(s4);        
            Transport.send(message);
            out.println("mail has been sent");
        } catch(Exception ex) {
            System.out.println("ERROR....."+ex);
        }
    }
}

I'm using mail.jar and activation.jar. But I can't understand how I should configure it with a mail server. Which mail server should I use? Will I be able to send an email using above code? What are the requirements a mail server? How should I configure it?