We have really struggled to resolve this issue that has been going on for a while now. We get this error intermittently when sending to various outside domains:A configuration error in the e-mail system caused the message to bounce between two servers or to be forwarded between two recipients. Contact your administrator.<ourservername.ourdomainname.com #5.3.5>It doesn't happen on all our e-mails, so it makes it really hard to troubleshoot. We only have one Exchange Server (Ex2003 SP2 Std Ed). This issue only seems to occur when we emailing a distribution group or a large number of single email addresses. Here is a list of the scenarios & solutions that have already been implemented: We do not have, nor need routing groups or connectors in our Exchange enviroment Removed SMTP connector in Exchange and restarted Routing Engine and SMTP service Windows and Exchange have been updated and patched as of this date Exchange Best Practice Analyzer has been run on server with these (unrelated) results: 3GB is not set HeapDeCommitFreeBlock Background Cleanup missing Afterwe receive the Email Error Message and choose to resend to an individual recipient, the email goes through fine. Any ideas or thoughts would be most appreciated, thanks.

Hi I have found we have that issue as well. In our case, the recipient MX record points to 127.0.0.1 which causes the message to loop on the Exchange server. They have deliberately done this to prevent them receiving email on this domain. If you do a nslookup set=mx <recipientdomain> and see what it returns as the IP address as the mail server. Has anyone found a way of getting exchange to drop these messages immediately? Cheers Peter

Hi, This doesn't look the case here.I have run the nslookup on recipient domains and the mail server IP's seem to be correct. Is it possible this is something to do with an error in Active Directory?

Hi it is unlikely to be an AD issue as exchange should be trying to deliver the message via DNS (unless you are forwarding to a smarthost). I resolved our issue by stopping the exchange server from listening on 127.0.0.1 In your case., I would turn logging up on exchange and see if that can help Cheers Peter

Hi Peter, I do appreciate the help... Are you saying that I should stop MY exchange server from listening on that port? I must have misunderstood and thought that it was something that my recipient IT people should do? Do you have instructions on how to do that by any chance? Thanks again

Alex We found that some of the bounce messages as the looping recipient weren't necessarily theone that caused the issue. On the SMtp vritual server, it is probably listening on all IP addresses. Drop the box down and change it so it only listens on the servers IP address and restart the SMTP service. Cheers Peter

I was really hoping this would be the one... We just tried to do another mass email and 24 out of 36 came back with the message. They were all addresses in the BCC field. Your message did not reach some or all of the intended recipients. Subject: Announcement: Unique Training Opportunity for Managers and Supervisors Sent: 2/14/2008 3:18 PM The following recipient(s) could not be reached: email@address.comon 2/14/2008 3:19 PM A configuration error in the e-mail system caused the message to bounce between two servers or to be forwarded between two recipients. Contact your administrator. <server.domain.com #5.3.5>