com.sun.mail.smtp.SMTPSendFailedException: 421 4.7.0 Try again later, closing connection. (MAIL) gl10sm923185pbc.41 - gsmtp

    at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:2057)
    at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1580)
    at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1097)
    at email.JavaEmail.sendEmail(JavaEmail.java:66)
    at MyTask.run(dateIncerement.java:33)
    at java.util.TimerThread.mainLoop(Timer.java:512)
    at java.util.TimerThread.run(Timer.java:462)

import email.JavaEmail;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import javax.mail.MessagingException;
import javax.mail.internet.AddressException;


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Lavanya
 */
class MyTask extends TimerTask{

   public void run()
   {
   JavaEmail email=new JavaEmail();
   try {
                    JavaEmail javaEmail = new JavaEmail();
                    javaEmail.setMailServerProperties();
                    javaEmail.createEmailMessage("satyavarapu.lavanya@gmail.com");
                    javaEmail.sendEmail();
                } catch (AddressException ex) {
                    ex.printStackTrace();
                } catch (MessagingException ex) {
                    ex.printStackTrace();
                }

   }
   }
 class dateIncerement1 extends TimerTask {
   public void run()
    {
        Date alertDate=null;

        Connection con = null;
        String url = ..........
        String dbName = .........
        String driver = ..........
        String userName = .........
        String password = .............

         try {

              Class.forName(driver).newInstance();
              con = DriverManager.getConnection(url+dbName,userName,password);
              System.out.println("Connected to the database");


                          String sql="select date from sample where name= 'radhika'" ;

                          Statement st=con.createStatement();
                          ResultSet rs=st.executeQuery(sql);
                          while(rs.next()){
                           alertDate=rs.getDate(1);

                          }



             }catch(Exception e){e.printStackTrace();}

        System.out.println("Last Login:"+alertDate);

Date now=new Date();
System.out.println(now);
if(now.compareTo(alertDate)>0)
System.out.println("comparing value:"+now);
System.out.println(alertDate);

Calendar test=Calendar.getInstance();
test.setTime(now);
test.add(test.DATE,-6);
Date testDate=test.getTime();
System.out.println("test date"+testDate);

Calendar cal = Calendar.getInstance();
//cal.set(2012,0,30,13,45);
cal.add(Calendar.DATE, 1); // <--
Date date1 = cal.getTime();
int day1=date1.getDate();
System.out.println(date1);


Calendar cal2=Calendar.getInstance();
//cal2.set(2012,0,30,13,47);
cal2.add(cal2.DATE,1);
Date date2=cal2.getTime();
int day2=date2.getDate();
System.out.println(date2);

Calendar cal3=Calendar.getInstance();
//cal3.set(2012,0,30,13,49);
cal3.add(cal3.DATE,1);
Date date3=cal3.getTime();
int day3=date3.getDate();
System.out.println(date3);

Calendar cal4=Calendar.getInstance();
//cal4.set(2012,0,30,13,51);
cal4.add(cal4.DATE,1);
Date date4=cal4.getTime();
int day4=date4.getDate();
System.out.println(date4);

Calendar cal5=Calendar.getInstance();
//cal5.set(2012,0,30,13,53);
cal5.add(cal5.DATE,1);
Date date5=cal5.getTime();
int day5=date5.getDate();
System.out.println(date5);

Calendar cal6=Calendar.getInstance();
//cal6.set(2012,0,30,13,55);
cal6.add(cal6.DATE,1);
Date date6=cal6.getTime();
int day6=date6.getDate();
System.out.println(date6);



             if (now.compareTo(alertDate)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), now);
                   System.out.println("email sent from alert date:");
                }

             if(now.compareTo(date1)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date1);
                    System.out.println("email sent from date1");
             }

             if(now.compareTo(date2)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date2);
                     System.out.println("email sent from date2");
              }

             if(now.compareTo(date3)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date3);
                     System.out.println("email sent from date3");
               }

             if(now.compareTo(date4)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date4);
                     System.out.println("email sent from date4");
                }

             if(now.compareTo(date5)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date5);
                     System.out.println("email sent from date5");
                 }

             if(now.compareTo(date6)> 0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date6);
                     System.out.println("email sent from date6");
                 }




    }
}
public class dateIncerement{
    public static void main(String args[])throws Exception{

        Date alertDate=null;


        Connection con = null;
        String url = ...
        String dbName = ...
        String driver = .....
        String password = ...

         try {

              Class.forName(driver).newInstance();
              con = DriverManager.getConnection(url+dbName,userName,password);
              System.out.println("Connected to the database");


                          String sql="select date from sample where name= 'radhika'" ;

                          Statement st=con.createStatement();
                          ResultSet rs=st.executeQuery(sql);
                          while(rs.next()){
                           alertDate=rs.getDate(1);

                          }



             }catch(Exception e){e.printStackTrace();}
        Date now=new Date();
        long period=24*60*60*1000;
        Timer timer1 = new Timer();
                    timer1.schedule(new dateIncerement1(), now,period);

    }

}

import email.JavaEmail;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import javax.mail.MessagingException;
import javax.mail.internet.AddressException;


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Lavanya
 */
class MyTask extends TimerTask{

   public void run()
   {
   JavaEmail email=new JavaEmail();
   try {
                    JavaEmail javaEmail = new JavaEmail();
                    javaEmail.setMailServerProperties();
                    javaEmail.createEmailMessage("satyavarapu.lavanya@gmail.com");
                    javaEmail.sendEmail();
                } catch (AddressException ex) {
                    ex.printStackTrace();
                } catch (MessagingException ex) {
                    ex.printStackTrace();
                }

   }
   }
 class dateIncerement1 extends TimerTask {
   public void run()
    {
        Date alertDate=null;

        Connection con = null;
        String url = ..........
        String dbName = .........
        String driver = ..........
        String userName = .........
        String password = .............

         try {

              Class.forName(driver).newInstance();
              con = DriverManager.getConnection(url+dbName,userName,password);
              System.out.println("Connected to the database");


                          String sql="select date from sample where name= 'radhika'" ;

                          Statement st=con.createStatement();
                          ResultSet rs=st.executeQuery(sql);
                          while(rs.next()){
                           alertDate=rs.getDate(1);

                          }



             }catch(Exception e){e.printStackTrace();}

        System.out.println("Last Login:"+alertDate);

Date now=new Date();
System.out.println(now);
if(now.compareTo(alertDate)>0)
System.out.println("comparing value:"+now);
System.out.println(alertDate);

Calendar test=Calendar.getInstance();
test.setTime(now);
test.add(test.DATE,-6);
Date testDate=test.getTime();
System.out.println("test date"+testDate);

Calendar cal = Calendar.getInstance();
//cal.set(2012,0,30,13,45);
cal.add(Calendar.DATE, 1); // <--
Date date1 = cal.getTime();
int day1=date1.getDate();
System.out.println(date1);


Calendar cal2=Calendar.getInstance();
//cal2.set(2012,0,30,13,47);
cal2.add(cal2.DATE,1);
Date date2=cal2.getTime();
int day2=date2.getDate();
System.out.println(date2);

Calendar cal3=Calendar.getInstance();
//cal3.set(2012,0,30,13,49);
cal3.add(cal3.DATE,1);
Date date3=cal3.getTime();
int day3=date3.getDate();
System.out.println(date3);

Calendar cal4=Calendar.getInstance();
//cal4.set(2012,0,30,13,51);
cal4.add(cal4.DATE,1);
Date date4=cal4.getTime();
int day4=date4.getDate();
System.out.println(date4);

Calendar cal5=Calendar.getInstance();
//cal5.set(2012,0,30,13,53);
cal5.add(cal5.DATE,1);
Date date5=cal5.getTime();
int day5=date5.getDate();
System.out.println(date5);

Calendar cal6=Calendar.getInstance();
//cal6.set(2012,0,30,13,55);
cal6.add(cal6.DATE,1);
Date date6=cal6.getTime();
int day6=date6.getDate();
System.out.println(date6);



             if (now.compareTo(alertDate)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), now);
                   System.out.println("email sent from alert date:");
                }

             if(now.compareTo(date1)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date1);
                    System.out.println("email sent from date1");
             }

             if(now.compareTo(date2)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date2);
                     System.out.println("email sent from date2");
              }

             if(now.compareTo(date3)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date3);
                     System.out.println("email sent from date3");
               }

             if(now.compareTo(date4)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date4);
                     System.out.println("email sent from date4");
                }

             if(now.compareTo(date5)>0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date5);
                     System.out.println("email sent from date5");
                 }

             if(now.compareTo(date6)> 0) {
                    Timer timer = new Timer();
                    timer.schedule(new MyTask(), date6);
                     System.out.println("email sent from date6");
                 }




    }
}
public class dateIncerement{
    public static void main(String args[])throws Exception{

        Date alertDate=null;


        Connection con = null;
        String url = ...
        String dbName = ...
        String driver = .....
        String password = ...

         try {

              Class.forName(driver).newInstance();
              con = DriverManager.getConnection(url+dbName,userName,password);
              System.out.println("Connected to the database");


                          String sql="select date from sample where name= 'radhika'" ;

                          Statement st=con.createStatement();
                          ResultSet rs=st.executeQuery(sql);
                          while(rs.next()){
                           alertDate=rs.getDate(1);

                          }



             }catch(Exception e){e.printStackTrace();}
        Date now=new Date();
        long period=24*60*60*1000;
        Timer timer1 = new Timer();
                    timer1.schedule(new dateIncerement1(), now,period);

    }

}