Generally we can send and receive messges normally. We do have one address that we used to be able to receive from with no problems. However, now that person can only send us an e-mail if they "reply" to one of our e-mails. If they originate an e-mail to us then it does not get delivered to our Exchange Server and they do not receive an NDR. It seems to me that it is something on their end but was wondering if anyone had any other thoughts on it. We use Exchange Server 2003 and we have the troubled e-mail address in our whitelist. Thanks, -- Pat