Dear all, My problem as following : No MAPI client can download the OAB, it shows 0X8004010F every time in the sync log.At the Exchange Server 2007 box, it logs the following in the Application log: Event ID: 9344 OALGen could not find the address list with the Active Directory object GUID of '/guid=CA6564F8F12BA84995A37889843630F4' in the list of available address lists. Please check the offline address list configuration object. - <Name>OAB Event ID: 9109 OALGen encountered an error 8004010f (internal ID 5000878) while generating address list '/guid=CA6564F8F12BA84995A37889843630F4'. Check other logged events to see if this is a serious error. - <Name>OAB Event ID: 9344 OALGen encountered error 8004010f while initializing the offline address list generation process. No offline address lists have been generated. Please check the event log for more information. - <Name>OAB After more investigation I found also the GUID folders in both D:\Exchange Server 2007\ExchangeOAB D:\Exchange Server 2007\ClientAccess\OAB Are empty and doesnt contain any file E.g.: OAB.xml Best Regards,

Hi, Please attempt following method to troubleshoot the issue: 1. EMC -> Organization Configuration -> Mailbox -> Offline Address Book 2. Right click Default Offline Address Book and click Properties 3. Under Address Lists tab, please select Include the default Global Address List and unselect Include the following Address Lists 4. Under Distribution tab, please ensure Enable Web-based distribution and Enable public folder distribution have been selected. 5. Restart System Attendant service and check the issue again. The problem may also occur if several AD objects missed, I suggest you prepare AD again on the Exchange environment by referring following article: Note: Please remember to force AD replication after prepare AD. http://technet.microsoft.com/zh-cn/library/bb288907(EXCHG.80).aspx If the issue still cannot be solved, I suggest you recreate the GAL and OAB to troubleshoot the issue. You can also refer to following article to troubleshoot the OAB generate issue: http://blogs.msdn.com/dgoldman/archive/2005/08/28/457378.aspx Mike