Unable to send Mails using Java Mail API [Using Gmail]

I have used following code which was working fine in year 2014 but currently its not working.

Credentials used in this code are also correct.

public class SendMail 
{  
public void SendMailToTheUserWhoHaveForgotThePassword(String MailTo,String Password)
  {      
      String to = MailTo;  
      String from = "chatna06062016@gmail.com";
      final String username = "chatna06062016";     
      final String password = "xxxxxxxx";  

      String host = "smtp.gmail.com";  
      Properties props = new Properties();
      props.put("mail.smtp.auth", "true");
      props.put("mail.smtp.starttls.enable", "true"); 
      props.put("mail.smtp.host", host);   
      props.put("mail.smtp.port", "25");  
      Session session = Session.getInstance(props,new javax.mail.Authenticator() 
                    {             
                        protected PasswordAuthentication getPasswordAuthentication() 
                        {                
                            return new PasswordAuthentication(username, password);     
                        }          
                    }
                                            );  

      try 
      {   
          Message message = new MimeMessage(session);            
          message.setFrom(new InternetAddress(from));       
          message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(to));        
          message.setSubject("FORGOTTEN PASSWORD"); 


          message.setText("Dear User The Password that you have forgotten is <b>"+Password +"</b>"+ 
                "This email is sended you by using JavaMailAPI "
                  + "HAVE A NICE DAY"
                  + "DO USE THIS SERVICE WHENEVER YOU NEED IT");  

    Transport.send(message);  
      System.out.println("Sent message successfully...."); 

      }
      catch (MessagingException e) { 
         throw new RuntimeException(e); 
      }

       }

} 

I have got email from google like this on the usage of the method used in above class.

Hi ChatNa,
Someone just tried to sign in to your Google Account chatna06062016@gmail.com from an app that doesn't meet modern security standards.
    Details:
Sunday, June 26, 2016 12:57 PM (India Standard Time)
Noida, Uttar Pradesh, India*
We strongly recommend that you use a secure app, like Gmail, to access your account. All apps made by Google meet these security standards. Using a less secure app, on the other hand, could leave your account vulnerable. Learn more.

Google stopped this sign-in attempt, but you should review your recently used devices:

What to do now unable to find out anything helpful anywhere.