send mail from yahoo id to other email ids using Javamail API
import javax.mail.*;
import javax.mail.internet.*;
import java.util.Properties;

public class MailExample {
    private static final String SMTP_HOST_NAME = "smtp.mail.yahoo.com";
    private static final int SMTP_HOST_PORT = 587;//465,587,25
    private static final String SMTP_AUTH_USER = "dummyrls@yahoo.com";
    private static final String SMTP_AUTH_PWD  = "my password";

    public static void main(String[] args) throws Exception{
       new MailExample().test();
    }

    public void test() throws Exception{
        Properties props = new Properties();

        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.host", SMTP_HOST_NAME);
        props.put("mail.smtp.auth", "true");
        // props.put("mail.smtps.quitwait", "false");

        Session mailSession = Session.getDefaultInstance(props);
        mailSession.setDebug(true);
        Transport transport = mailSession.getTransport();

        MimeMessage message = new MimeMessage(mailSession);
        message.setSubject("Testing SMTP-SSL");
        message.setContent("This is a test", "text/plain");

        message.addRecipient(Message.RecipientType.TO,
             new InternetAddress("rlss@abc.com"));

        transport.connect
          (SMTP_HOST_NAME, SMTP_HOST_PORT, SMTP_AUTH_USER, SMTP_AUTH_PWD);

        transport.sendMessage(message,
            message.getRecipients(Message.RecipientType.TO));
        transport.close();
    }
}

DEBUG: setDebug: JavaMail version 1.4.1 DEBUG: getProvider()
  returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,
  Sun Microsystems, Inc.,1.4.1] DEBUG SMTP: useEhlo true,
  useAuth true
DEBUG SMTP: trying to connect to host "smtp.mail.yahoo.com", port 587,
  isSSL false Exception in thread "main"
javax.mail.MessagingException: Could not connect to SMTP
  host: smtp.mail.yahoo.com, port: 587;   nested exception is:
java.net.ConnectException: Connection timed out: connect
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1391)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:412)
at javax.mail.Service.connect(Service.java:288)
at com.sample.mailexample.MailExample.test(MailExample.java:313)
at com.sample.mailexample.MailExample.main(MailExample.java:291) Caused by:
   java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:233)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1359)
... 4 more

public class SendMail {

    String host, port, emailid,username, password;
    Properties props = System.getProperties();
    Session l_session = null;

    public BSendMail() {
        host = "smtp.mail.yahoo.com";
        port = "587";
        emailid = "a@yahoo.com";
        username = "a";
        password = "pwd";

        emailSettings();
        createSession();
        sendMessage("a@yahoo.com", "rahul@gmail.com","Test","test Mail");
    }

    public void emailSettings() {
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.auth", "true");
        props.put("mail.debug", "false");
        props.put("mail.smtp.port", port);
//        props.put("mail.smtp.socketFactory.port", port);
//        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
//        props.put("mail.smtp.socketFactory.fallback", "false");

    }

    public void createSession() {

        l_session = Session.getInstance(props,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(username, password);
                    }
                });

        l_session.setDebug(true); // Enable the debug mode

    }

    public boolean sendMessage(String emailFromUser, String toEmail, String subject, String msg) {
        //System.out.println("Inside sendMessage 2 :: >> ");
        try {
            //System.out.println("Sending Message *********************************** ");
            MimeMessage message = new MimeMessage(l_session);
            emailid = emailFromUser;
            //System.out.println("mail id in property ============= >>>>>>>>>>>>>> " + emailid);
            //message.setFrom(new InternetAddress(emailid));
            message.setFrom(new InternetAddress(this.emailid));

            message.addRecipient(Message.RecipientType.TO, new InternetAddress(toEmail));
            message.addRecipient(Message.RecipientType.BCC, new InternetAddress(AppConstants.fromEmail));
            message.setSubject(subject);
            message.setContent(msg, "text/html");

            //message.setText(msg);
            Transport.send(message);
            System.out.println("Message Sent");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }//end catch block
        return true;
    }

}