Exchange can't do this. You can set it up so the NDR's go to a mailbox
Tony Woods MCSE, CNA
Exchange FAQ - http://www.swinc.com/resource/exch_faq.htm
I would like to configure an Exchange server to accept all inbound e-mails
for a domain, even if the intended recipient does not exist. When an e-mail
comes in for the proper domain, the Exchange server should accept it, look
for a match in the recipients and then deliver it to a default mailbox when
no matching recipient is found.