Delivery Status Notification (Failure)

my internet email server (exchange) is getting hammer by over seas spammers. Although we have a firewall and Antigen blocking based on blacklists, thousands of messages are reaching our email server and filling the queues. The queues are filled with outbound message to the spammers with a notice of delivery failure. In Exchange, can I turn stop the server from sending failure notices from Postmaster@ ??

Thanks
John

 

The MS document Arie found is good.
Also do a google search for "Open SMTP Relay "
If your clients don't send mail from the wan side relaying through the exchange box then by all means close port 25.

 

Thanks, I was in panic mode yesterday. I follow the instructions in the document. I will keep an eye on the queues and see what happens.

John

 

An update

Thanks for the help, After checking on the links you guys provided, I found that our exchange server was locked down. However the guy the configured our new firewall had the NAT set on Wan1-->Internal so that out side addresses looked like inside addresses. Hence the exhange server would relay the message. All is well now. The forum is a great source of help. Thanks again

John