Hi allHope you can help me with this one.First of all some backgound:-This is a windows 2003 enterprise server running 2003 exchange enterprise.The server has been running fine for 6 months.It is also the DC.(Only server on the network)I receive hundreds of the error below and the server has to be restarted to get back up and running again.Event Type:ErrorEvent Source:MSExchangeALEvent Category:LDAP Operations Event ID:8026Date:17/09/2006Time:00:15:03User:N/AComputer:VIKINGDescription:LDAP Bind was unsuccessful on directory viking.medigoldhealth.mhl for distinguished name ''. Directory returned error:[0x51] Server Down.Event Type:ErrorEvent Source:MSExchangeDSAccessEvent Category:Topology Event ID:2104Date:17/09/2006Time:00:15:18User:N/AComputer:VIKINGDescription:Process MAD.EXE (PID=4000). All the DS Servers in domain are not responding. Event Type:ErrorEvent Source:UserenvEvent Category:NoneEvent ID:1030Date:17/09/2006Time:00:15:06User:NT AUTHORITY\SYSTEMComputer:VIKINGDescription:Windows cannot query for the list of Group Policy objects. Check the event log for possible messages previously logged by the policy engine that describes the reason for this.Now this is what I have done so far:-I have ran netdiag and dcdiag both passing ok.I have checked the receipient update policy in system manager and the domain/exchange server/ and windows domain controller all appear to be correct.Any help would be greatly appreciated.Many thanksKev

I had this same issue, turned out the Exchange SRS service was stopped. Restarted this service, errors stopped.

Hello, I have the same error on a fresh install. All suggested options above are right on my server. I have runned dcdiag and netdiag without any problems. Does anyone have an idea how to fix this problem? Thnx

http://support.microsoft.com/kb/310896

I have more than 2 Domain Controllers and I see the same error on my servers. The link you inserted does not solve the problem. Max

what about your DNS settings on DNS server itself and on clients. http://support.microsoft.com/kb/258181