Whenwe "demote" the "front-end" server (OMA)on my Windows 2003 Exchange server, on the "back-end" server users cannot send mail to the outside world. 1. Users can receive from the outside and inside.2. Users can send to the inside.But they cannot send email to the outside world and OMA doesn't work. We have checked the firewall and nothing is being blocke and all the Exchange Services have been restarted on the back end server.What are we missing in the steps?Also I am getting this message in the Event viewer on the back end server:Event ID 4515The zone sassenheim.emea.sensitech.nl was previously loaded from the directory partition DomainDnsZones.sassenheim.emea.sensiteh.nl but another copy of the zone has been found in the directory partititon ForestDnsZones.sassenheim.emea.sensitech.nl. The DNS Server will ignore this new copy of the zone. Pleae resolve the confilct as soon as possible.

Please don't cross post questions. I'm not sure what you mean by "demote the front-end server" but you need to resolve the dns zone issue. Have you run ExBPA to see what kind of error's it is showing?ThanksWillWill Shepherd - MCSE/MCITP/MCTS (Windows 2008,Exchange 2007,OCS 2007)

I didn't cross post. I realized this was a better forum to get my answer.In any case, you may want to familiarize yourself with this concept: http://technet.microsoft.com/en-us/library/aa997801(EXCHG.65).aspxIs there anyone else out there who can assist? Thanks.

Wow really. Sorry I tried to get more information to help you I guess you don't need it. By the way RUN ExBPA!!!!Will Shepherd - MCSE/MCITP/MCTS (Windows 2008,Exchange 2007,OCS 2007)

Hi, Would you please let me know whether any NDR message is received when attempting to send message to external recipient or the message just stuck on your Exchange 2003 Backend Server and then expired? If any NDR message is received, please post the related NDR message here. If the message stuck on the Exchange Server, please refer to following article to troubleshoot the issue: How to use Queue Viewer to troubleshoot mail flow issues in Exchange Server 2003 http://support.microsoft.com/kb/823489/en-us ~~~~~~~~~~~~~~~~ Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com ~~~~~~~~~~~~~~~~