How to catch invalid emails & How to send to multiple emails

Question

This is a long two-part question.
Part One:
I would like to catch invalid emails within the JavaMail code and send the valid emails. I am using the following code to do this. The problem I am running into is when there is a valid email, sometimes it will be caught within the code without being sent and it will show up as a validunsentemail. I have set sendpartial to true, so this shouldn't be happening. Also, is there a way to check if a domain name is in existence before sending the email?
Part Two:
For testing purposes, I would like to mix valid and invalid emails for TO, but I don't know how to send to more than one email using an array. I have looked at other posting on the forum of how to do this, but I keep getting errors when I try other's suggestions. Maybe somebody will be able to help with this problem if they see the code below.
Thanks in advance for all your help!
import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;
import javax.mail.event.*;
import javax.activation.*;
public class Practice
public static void main (String[] args) {
Transport trans = null;
try {
Properties props = System.getProperties();
props.put("mail.smtp.host", "hostname");
props.put("mail.smtp.sendpartial","true");
Session mailConnection = Session.getDefaultInstance(props, null);
Message msg = new MimeMessage(mailConnection);
Address angela= new InternetAddress("[email protected]");
InternetAddress[] address ={new InternetAddress("[email protected]")};
msg.setRecipients(Message.RecipientType.TO, address);
msg.setContent("This is a test. This is only a test. What's Next?", "text/plain");
msg.setFrom(angela);
msg.setSubject("Testing 123");
msg.setSentDate(new Date());
msg.saveChanges();
trans = mailConnection.getTransport(address[0]);
trans.connect();
trans.send(msg, address);
System.out.println("Mail was sent successfully.");
try {Thread.sleep(5);}catch(InterruptedException e){}
} catch (MessagingException mex){
try {Thread.sleep(5);}catch(InterruptedException e){}
mex.printStackTrace();
System.out.println();
Exception ex = mex;
do{
if (ex instanceof SendFailedException){
SendFailedException sfex = (SendFailedException) ex;
Address[] invalid = sfex.getInvalidAddresses();
if (invalid != null){
System.out.println(" ** Invalid Addresses");
if (invalid != null) {
for (int i=0; i< invalid.length; i++)
System.out.println(" " + invalid);
Address[] validUnsent = sfex.getValidUnsentAddresses();
if (validUnsent != null){
System.out.println(" ** ValidUnsent Addresses");
if (validUnsent !=null){
for (int i=0; i<validUnsent.length; i++)
System.out.println(" "+validUnsent[i]);
Address[] validSent = sfex.getValidSentAddresses();
if (validSent != null){
System.out.println(" **ValidSent Addresses");
if (validSent != null){
for (int i=0; i<validSent.length; i++)
System.out.println(" "+validSent[i]);
System.out.println();
if (ex instanceof MessagingException)
ex = ((MessagingException)ex).getNextException();
else
ex = null;
} while (ex != null);
} finally {
try {
trans.close();
} catch (MessagingException mex){  /*  ignore */}

Answer 1

I am working on exactly the same problem. What you need to do is use the destination mail server to send mails. For example: address
[email protected] is an invalid user.
Using normal way you wont be able to catch invalid mail box error.
If you use mail server of jabcreative.com to send email then you will get an unknown user exception.
To find mail server of jabcreative.com you will have to do MX LookUp on DNS entry
Have a look at this URL
http://www.cee.hw.ac.uk/courses/5nn2/3/12.htm