JavaMail api question..

Question

I'am trying to send an e_mail to myself using the javaMail API.
I have already installed it (and also the Java Activation Framework).
The code is:
import javax.mail.*;
import javax.mail.internet.*;
import java.util.Properties;
import java.util.Date;
import java.io.*;
public class PruebaMail {
public static void main(String[] argv) {
          try {
               Properties props = new Properties();
               Session sendMailSession;
               Store store;
               Transport transport;
               sendMailSession = Session.getInstance(props, null);
               props.put("mail.smtp.host", "SMTP.mail.yahoo.com");
               Message newMessage = new MimeMessage(sendMailSession);
               newMessage.setFrom(new InternetAddress("[email protected]"));
               newMessage.setRecipient(Message.RecipientType.TO, new InternetAddress("[email protected]"));
               newMessage.setSubject("Prueba 1234");
               newMessage.setSentDate(new Date());
               newMessage.setText("Le escribimos para informarle que alguien ha respondido a su consulta");
               transport = sendMailSession.getTransport("smtp");
               transport.send(newMessage);
          } catch (MessagingException e1) {
          System.out.println("PruebaMail MessagingException:" + e1.getMessage());
.. but, issuing C:\>java PruebaMail .. I get this error:
PruebaMail MessagingException:Sending failed;
nested exception is:
     javax.mail.MessagingException: Unknown SMTP host: SMTP.mail.yahoo.com;
nested exception is:
     java.net.UnknownHostException: SMTP.mail.yahoo.com
so, my question is:
1. What is wrong in my code. Do you know an available SMTP server which
allows relaying??
thanks in advance!

Answer 1

Reverse this order:
sendMailSession = Session.getInstance(props, null);
props.put("mail.smtp.host", "SMTP.mail.yahoo.com");Any property should be set before getting a Session instance.
If your mail server expects authentication you should give one more property, so the code will be:
if(user != null) // should be authenticated
  props.put("mail.smtp.auth", "true");
else
  props.put("mail.smtp.auth", "false");
props.put("mail.smtp.host", "SMTP.mail.yahoo.com");
sendMailSession = Session.getInstance(props, null);
... // fill newMessage
if(user != null) { // should be authenticated
  newMessage.saveChanges();
  Transport transport = session.getTransport("smtp");
  transport.connect(mailhost, user, password);
  transport.sendMessage(newMessage, newMessage.getAllRecipients());
  transport.close();
else
  Transport.send(newMessage);