HiCan anybody verify, that having a large address list in OWA would fail quering AD for members?I have about 25.000 users in one of my address lists, and quering this list, it fails with the following error.ExceptionException type: Microsoft.Exchange.Data.Directory.ADInvalidHandleCookieExceptionException message: Active Directory operation failed on Eucnvsdc2.eucnvs.esis.dk. Additional information: Additional information: The directory service encountered an unknown failure. Active directory response: 000020EF: SvcErr: DSID-03140312, problem 5010 (UNAVAIL_EXTENSION), data 0 .

Hi, 1. I recommend you to follow the MaxTempTableSize on the DC to a value higher than the 10000 default. 2. Then change value on msExchQueryBaseDN. MaxTempTableSize: While a query is processed, the dblayer may try to create a temporary database table to sort and select intermediate results from. The MaxTempTableSize limit controls how large this temporary database table can be. If the temporary database table would contain more objects than the value for MaxTempTableSize, the dblayer performs a much less efficient parsing of the complete DS database and of all the objects in the DS database.msExchQueryBaseDN is the mechanism used to limit certain users to see only a subsection of the address book in OWA. msExchQueryBaseDN is stamped on Active Directory user objects and points to an Address List (AL) or an Organizational Unit (OU). This AL will be used as the Global Address List (GAL) for the user, and the user will see a GAL including only user accounts in this OU. You can setmsExchQueryBaseDN using LDAP. How to view and set LDAP policy in Active Directory by using Ntdsutil.exe http://support.microsoft.com/default.aspx/kb/315071 How to set the msExchQueryBaseDN attribute for users via powershell http://blogs.msdn.com/dgoldman/archive/2009/01/08/how-to-set-the-msexchquerybasedn-via-powershell.aspx How to restrict OWA address searches to multiple organizational units http://support.microsoft.com/kb/817218 Regards, Xiu