Java EE (Java Enterprise Edition) General Discussion

I m tring to send a mail using SMTP gmail server.
but not able to connect to the server.
Please can somebody help me.
class TestEmail1 {
public static void main(String args[]){
String host = "smtp.gmail.com";
Properties props = new Properties();
props.put("mail.transport.protocol", "smtp");
props.put("mail.smtp.host", "smtp.gmail.com");


Session session = Session.getInstance(props,null);
MimeMessage message = new MimeMessage(session);
try{
message.setFrom(new InternetAddress("shirishmety@gmail.com"));
message.addRecipient(Message.RecipientType.TO,
new InternetAddress("shirish2001@yahoo.com",false));
message.setSubject("Hello JavaMail");
message.setText("Welcome to JavaMail");

Transport.send(message);
}catch (AddressException e) {
e.printStackTrace();
}catch (MessagingException e) {
e.printStackTrace();
}
}
}

I m getting these many errors
javax.mail.MessagingException: Unknown SMTP host: smtp.gmail.com;
nested exception is:
java.net.UnknownHostException: smtp.gmail.com
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1280)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
at javax.mail.Service.connect(Service.java:275)
at javax.mail.Service.connect(Service.java:156)
at javax.mail.Service.connect(Service.java:105)
at javax.mail.Transport.send0(Transport.java:168)
at javax.mail.Transport.send(Transport.java:98)
at TestEmail1.main(TestEmail1.java:22)
Caused by: java.net.UnknownHostException: smtp.gmail.com
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:232)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1250)

any help will be apreiciated