Hi All, Could use some help, I have aexchange server ver. 2003 Sp2 running on a windows server 2003. Lately some of my user as well as customers are getting bounce backs on the messages being sent to us. If they send it again it will go through. The numeric error code is 5.7.1. Can anyone help resolve this? It started happening a few weeks ago but is happening with more frequency lately. Thanks any feed back will be grateful Ron C.

check out: Delivery Status Notifications in Exchange 2000/2003 Server http://support.microsoft.com/default.aspx?scid=kb;en-us;284204&Product=exchange "...Numeric Code: 5.7.1Possible Causes: General access denied, sender access denied - the sender of the message does not have the privileges required to complete delivery. You are trying to relay your mail through another SMTP server and it does not permit you to relay. The recipient might have mailbox delivery restrictions enabled. For example, a recipient's mailbox delivery restriction was set to receive from a Distribution List only and non-members' email will be rejected with this error. For Exchange Server 2003, a distribution list can be configured to restrict mail delivery from unauthenticated users. Mail that is sent by using an unauthenticated SMTP session are rejected.Troubleshooting: Check system privileges and attributes for the contact and retry the message. Also, make sure you are running Exchange 2000 Service Pack 1 or later for other potential known issues..."

Hi Mike, Thanks for your response I had already read that article and should have noted that in my request. I did work out the issue it involved my ISP and hosting company. Here is what I found; Our ISP and hosting company both thought they were hosting our DNS, the ISP was pointing to their webpage which caused bounce back and our hosting company was pointing to there internal mailboxes which we were not using. After numerous discussions we were able to iron out the problem. First I had the ISP release all hosting of our DNS. This took care of part of the problem then I had our hosting company check our MX record and had that redone so it pointed to our in house exchange server with its variations. After that we have not had any bounce backs to date caused by being pointed to the wrong server. Thank you again for getting back to me it is appreciated. RC

glad you got it worked out!I think i read once that says 80% of all networking issues are related in some way to DNS