Hi to anyone, Hopefully someone can help on this problem which was initially working but NOT now. Had one exchange 2003 server with site address gcsg.com and another named as gcpl.com. Both exchange 2003 servers are on different networks and had different IP Addresses. We had another server which runs the DNS and this server comes with the domain gc.com. Therefore, emails being sent to gc.com will be forwarded to gcsg.com and from gcsg.com to gcpl.com. Now, users from gcsg.com had no problems at all sending emails to anyone in gc.com domain. However, users from gcpl.com cannot send a single email to gc.com users at all! It will always return an error of user not found, error code 5.1.1. I am not too sure how to solve this.Users under gcpl.com had two email addresses associated to them (user@gc.com as the default one and user@gcpl.com) and sending emails to anywhere works except gc.com. No connectors etc are configured on the server at all. Hope someone is able to understand what I am facing above and do help to provide some ideas on how to overcome this. Many thanks in advance, Tan

Hi, Sounds as if you are sharing the domain name. This should help: http://support.microsoft.com/default.aspx?kbid=321721 Leif

Hello Leif, Thanks for the information. I had tried what was in the document and nothing works. I am not too sure why this is so but I am sure that I had followed the instructions one by one. Still nothing works. I then turned on all the SMTP diagnostics logging to maximum and found something interesting. The information is as follows: Event ID 984 SMTP GetNextHope returned hr=0x0 in 0ms DestAddr=<a.sg.com> Type=<SMTP> MsgType=0x0 NextHopType=Other_Routing_Group Type=<SMTP> Class = <a.sg.com> Schedl d=0xffffffff RouteAddr=<a.sg.com> Connector=<DNS> There are problems with the above as the DestAddr, RouteAddr and Class are all pointing to a wrong address. The server that I had problems sending to is "a-sg.com" and clearly something was wrong when the DNS look it up. Can you tell me where do I change the above so that everything works? I had double check on the DNS servers (2 running) and cannot findanything related to<a.sg.com> . Thanks, Tan

Anyone had any ideas what's wrong? I had checked on the DNS settings and found nothing wrong. When I used the connector to try sending emails to the other server, I got the error about authentication needed. Not too sure about what could be wrong at all now.