How to send e-mail using JavaMail APIs ?

public class SendMailServlet extends HttpServlet {

  String smtpServer;

  public void init (ServletConfig config) throws ServletException {

     // get the SMTP server from the servlet properties

     smtpServer = config.getInitParameter("smtpServer");

  }

  public void doPost(HttpServletRequest req, HttpServletResponse res)
                     throws ServletException, IOException {

     // get the message parameters from the HTML page

     String from = req.getParameter("from");

     String to = req.getParameter("to");

     String subject = req.getParameter("subject");

     String text = req.getParameter("text");

     PrintWriter out = res.getWriter();

     res.setContentType("text/html");

     try {

        // set the SMTP host property value

        Properties properties = System.getProperties();

        properties.put("mail.smtp.host", smtpServer);

        // create a JavaMail session

        Session session = Session.getInstance(properties, null);

        // create a new MIME message

        MimeMessage message = new MimeMessage(session);

        // set the from address

        Address fromAddress = new InternetAddress(from);

        message.setFrom(fromAddress);

        // set the to address

        if (to != null) {

           Address[ ]  toAddress = InternetAddress.parse(to);

           message.setRecipients(Message.RecipientType.TO, toAddress);

        } else {

          throw new MessagingException("No \"To\" address specified");

        }

 

         // set the subject

         message.setSubject(subject);

         // set the message body

         message.setText(text);

         // send the message

         Transport.send(message);

         out.println("Message sent successfully.");

     } catch (AddressException e) {

         out.println("Invalid e-mail address.<br>" + e.getMessage());

     } catch (SendFailedException e) {

         out.println("Send failed.<br>" + e.getMessage());

     } catch (MessagingException e) {

         out.println("Unexpected error.<br>" + e.getMessage());

     }

  }

}