Hi there, Appreciate someone could give me some hint on the solution. We have few Exchange servers in branches that all connected to HQ Exchange server via Routing Group Connector. All emails among the branch offices and from External are delivered from HQ Exchange 2003 to the branch Exchange 2003 server. Recently Branch-A patch their Exchange server 2003, and after the patch the Routing Group Connector between branch-A and HQstop working. We thought it is due to patch problem, therefore we uninstall patch, still probelm persist. Then we rebuild the server from OS level and reinstall Exchange 2003 without any further patching, it still problem. We then setup another Exchange 2003 server on separate hardware into same SITE, and use that new server only for Routing Group connection to HQ, it works perfectly. We are running out of idea, and the only think one that we suspect is possible due to the server name, as when we rebuild the existing problematic server, we use back the same server name. If this the problem, how can we get that corrected ? When we force the Routing Group connection from HQ Exchange 2003 (from Exchange Systems Mgr -> Queues) we can see from the network the SMTP traffic passing, and sametime when we perform telnet port 25 from HQ Exchange we notice a response from Exchange 2003 in Branch-A. So network is not a problem. We struggle for a month, and I really hope I can get something before we perform another rebuild of the Exchange 2003 again. thanks in advance