Java EE (Java Enterprise Edition) General Discussion

I searched the forum and found the following post. I have the exact same problem now.

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Hi, I'm using javax.mail.event.TransportListener for detecting if emails are delivered to the recipient or not.
The mechanism technically works, but i have a problem.
We have an intranet SMTP server and an extranet SMTP server.
When i use the intranet server, any e-address (even if the recipient is xxx@yyy.zz) is considered valid and i always get the event messageDelivered.
I think it's because it just delivers the email to the extra SMTPserver.
When i use the extranet server, any e-address with my internal domain (e.g. xxx@mydomain.it) is valid , any e-address with no dots in the domain (e.g. xxx@yyzz) is valid , but any e-address with at least one dot and not with my domain (e.g. xxx@yy.zz) in the domain is not valid (i get javax.mail.SendFailedException: 554 Relay rejected for policy reasons.).
I know what relay means, but i don't understand why domain with no dots are considered valid (i'd like to be notified when they are not existing addresses).
Does it all depend on my SMTPservers' policy or can i do something for getting an invalid address when the address is invalid, such for example xxx@yyzz?

Maybe the only way for having a notification is by means of the DELIVERY FAILURE email i receive, after a while, from the router server?

Thanks for help
Fulvia
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So is there any solution for that without touching SMTP server configuration. Or any walkaround ways to successfully send email?
Any ideas and suggestions will be greatly appreciated.
The original post link is :
http://forum.java.sun.com/thread.jsp?forum=43&thread=403000