Class MessagingException not working as I think it should - email

Question

I'm developing a web application that sends an email and has to check, that, in fact this mail has been delivered from my application side as much as possible in few seconds (I don't think you can do more than getting that the email has been delivered to email server, if that email server later cannot later send that email to the user that uses it because it has its inbox full or another situation like this, I think it cannot be helped, although if there's some way I'd like to know about it).
Anyway one thing I think could be checked without problems is if the email address doesn't exist as that gives an inmediate response, according to what I've read this could be done with class MessageException, but I've the following code:
String email=Utils.parseString(req,"email");
[....]
Properties props = new Properties();
props.put("mail.smtp.host", "smtp.gmail.com");
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.EnableSSL.enable","true");
Session s = Session.getInstance(props, null);
MimeMessage message = new MimeMessage(s);
try {
InternetAddress from = new InternetAddress(emailadressthatworks);
message.setFrom(from);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return;
}
try {
InternetAddress to = new InternetAddress(email);
message.addRecipient(Message.RecipientType.TO, to);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
resp.sendRedirect("webpage.jsp");
return;
}
try {
message.setSubject("Subject");
message.setText("message");
Transport.send(message);
} catch (MessagingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
resp.sendRedirect("webpage.jsp");
return;
}
[....]
And whatever random String I asign to email it never throws an MessagingException in Transport.send(message); so I can redirect it to another jsp web page when I think it should according to what I have read.
Might I be missing something or is it that this class cannot detect that things?
Thanks for your help.

Answer 1

Use the strict InternetAddress constructor and call message.saveChanges() to perform the validation. See
Content-Type syntax check throws exception too late for more details.

Answer 2

See this JavaMail FAQ entry.
Also, it's up to your mail server whether it tries to detect some kinds of errors immediately or whether it queues all requests and only checks for errors later.