Java Mail API Enviar e-mails da propria maquina

package controller;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;

public class SendMail{
	private String to, from, host;
	private Properties properties;
	private Session session;
	public SendMail(){
		
	}
	public void enviar(){
      to = "[email removido]";
      from = "[email removido]";
      host = "localhost";
      
     properties = System.getProperties();
     properties.setProperty("mail.smtp.host", host);
     
     session = Session.getDefaultInstance(properties);

      try{
         MimeMessage message = new MimeMessage(session);
         
         message.setFrom(new InternetAddress(from));
         message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
         message.setSubject("teste");
         message.setText("teste de envio");
         // enviando o email
         Transport.send(message);
         System.out.println("Email enviado com sucesso");
      }catch (MessagingException e) {
         e.printStackTrace();
      }
   }
	
	public static void main(String args[]){
		SendMail email = new SendMail();
		email.enviar();
	}
}

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
  nested exception is:
	java.net.ConnectException: Connection refused
	at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1934)
	at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:638)
	at javax.mail.Service.connect(Service.java:295)
	at javax.mail.Service.connect(Service.java:176)
	at javax.mail.Service.connect(Service.java:125)
	at javax.mail.Transport.send0(Transport.java:194)
	at javax.mail.Transport.send(Transport.java:124)
	at controller.SendMail.enviar(SendMail.java:32)
	at controller.SendMail.main(SendMail.java:41)
Caused by: java.net.ConnectException: Connection refused
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:310)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:176)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:163)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384)
	at java.net.Socket.connect(Socket.java:546)
	at java.net.Socket.connect(Socket.java:495)
	at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:288)
	at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:231)
	at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1900)
	... 8 more