Hello, I have been frustrated in my attempts at installing AD/Exchange in a new environment consisting of 2 machines, one for AD, one for Exchange. I got AD running on Windows 2003 Server. I installed Windows 2003 64 bit edition on 2nd server (4GB RAM), bound to the AD domain, and tried to do a typical install of Exchange 2007 following all the steps. It successfully completes Copy Exchange Files, installs Hub Transport Role, Client Access role, However, I repeatedly get an error at Mailbox Role install. The error says: "The Exchange Server address list service failed to respond. This could be because of an address list or email address policy configuration error." I tried all 3 resolutions mentioned on http://support.microsoft.com/kb/935636, but that does not help. I have even tried reconfiguring AD and re-installing Exchange, but keep getting the same error. Any help or pointers would be highly appreciated. I am getting frustrated... Thanks, Vivek====== [4/1/2008 7:10:51 PM] [1] Exception : Microsoft.Exchange.Configuration.MonadDataProvider.MonadDataAdapterInvocationException: The Exchange server address list service failed to respond. This could be because of an address list or email address policy configuration error. It was running command '$error.Clear(); $count=0; $ExchangeServers = Get-ExchangeServer -DomainController $RoleDomainController; foreach($server in $ExchangeServers) { if(($server.AdminDisplayVersion.Build -gt 641) -and ($server.IsMailboxServer -eq $true)) { $count++; } } if( $count -eq 1) { Set-OrganizationConfig -DomainController $RoleDomainController; }'. ---> Microsoft.Exchange.Data.Directory.RusServerUnavailableException: The Exchange server address list service failed to respond. This could be because of an address list or email address policy configuration error. at Microsoft.Exchange.Data.Directory.Recipient.RecipientUpdateService.LocateServer() at Microsoft.Exchange.Configuration.Tasks.RecipientTaskHelper.ApplyRusPolicy(ADSystemConfigurationSession configurationSession, ADRecipientSession recipientSession, ADRecipient recipient, Fqdn domainController, String serverName, TaskVerboseLoggingDelegate logHandler, TaskWarningLoggingDelegate writeWarning) at Microsoft.Exchange.Configuration.Tasks.RecipientTaskHelper.ApplyRusPolicy(ADSystemConfigurationSession configurationSession, ADRecipientSession recipientSession, ADRecipient recipient, Fqdn domainController, String serverName, TaskVerboseLoggingDelegate logHandler, TaskErrorLoggingDelegate writeError, TaskErrorLoggingDelegate throwTerminatingError, TaskWarningLoggingDelegate writeWarning) --- End of inner exception stack trace --- at Microsoft.Exchange.Configuration.MonadDataProvider.MonadCommand.ClosePipeline(MonadAsyncResult asyncResult) at Microsoft.Exchange.Configuration.MonadDataProvider.MonadCommand.EndExecute(MonadAsyncResult asyncResult) at Microsoft.Exchange.Management.Deployment.ComponentInfoBasedTask.ExecuteScript(String script, Boolean handleError, Int32 subSteps, LocalizedString statusDescription) at Microsoft.Exchange.Management.Deployment.ComponentInfoBasedTask.GenerateAndExecuteTaskScript(InstallationCircumstances installationCircumstance)