Hi We have two exchange 2003 cluster with five domain controller of Windows 2003 all have latest SP level. Administrator has XP with PC and exchange 2003 administrator program installed on it PC has all latest SP level Now from XP when we open AD users and computer MMC and try to modify any users account email address it take logn time to come up dialog box When we take property of user account and select Email Address tab upto here is very fast but when we press modify button of email address it take long time to come up diaglog box for modifying email address some time it is 30 mimutes average is 15 mimutes Any body has any idea Nagori

How many Exchange servers do you have? Are they all in the same physical location as you? I saw a weird problem recently where the clients were connecting to remote Exchange servers when the Email Addresses were being validated. It is necessary for Active Directory Users and Computers to do this so that it can verify that the e-mail address format is correct.

Hi, It may cause by the LDAP query timeout value which is not configurable. Please follow the below steps to try to troubleshoot this issue.1. First you can run the following query to determine which server is returned by the LDAP query: ldifde -f out.txt -s win2k3dc-ex1.nwtraders.msft -d "cn=Microsoft Exchange,cn=Services,cn=Configuration,dc=nwtraders,dc=msft" -r "(objectCategory=msExchExchangeServer)" 2. Then please make sure 139 and 445 has been opened. 3. After that please apply the hot fix listed below: Active Directory Users and Computers may stop responding when you use Active Directory Users and Computers on a server that is not running Exchange Server 2003 to change a user's proxy addresshttp://support.microsoft.com/default.aspx?scid=kb;EN-US;895668 4. After that, please add a registry key on the client machine you are running ADUC from:1. Click Start, click Run, type regedit in the Open box, and then click OK. 2. Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMGMT\Parameters 3. On the Edit menu, point to New, and then click String Value. 4. Name the new registry entry "Preferred SA Server". 5. Right-click Preferred SA Server, and then click Modify. 6. In the Value data box, type the NetBIOS name of a Exchange server close to you, and then click OK. If above steps do not help, then you can open ADUC from client computer then click on Action-Connect to Domain Controller. Here please try to connect these 5 domain controller to see whether the issue will occur. You may have a look at the below article: How to optimize Active Directory replication in a large network http://support.microsoft.com/kb/244368/ Besides, please try to check the NIC configuration on DC, whether it has been set to half duplex. If so, set them to full duplex. Meanwhile please update the NIC driver. More information share with you: You may receive an "RPC server is too busy to complete this operation" error message when you try to log on to a computer that is running Windows Server 2003 with Service Pack 1http://support.microsoft.com/default.aspx?scid=kb;EN-US;905700 You receive an "ID no: c10308a2" error message when you use the Active Directory Users and Computers snap-in to remotely add or edit an e-mail address for a mail-enabled user in Exchange Server 2003http://support.microsoft.com/default.aspx?scid=kb;EN-US;905809 Hope it helps. Xiu