I've recently stood up Exchange 2010 in my pre-existing Exchange 2003 organization and just setup a new OAB for the Exchange 2010 users and am getting the following warning events. Any ideas on how I can resolve this. Thanks, Abdu Event ID 9399 OALGen is configured to generate version 4 OAB files for offline address book '\2010 OAB' and publish it to public folders, but there is no public folder server available. OAB version 4 will be generated but will not be published to a public folder at this time. Please ensure that a public folder server with a replica of the Offline Address Book system folder is online and mounted, or disable publishing OAB version 4 to public folders. Event ID 9386 OALGen is configured to generate version 2 or version 3 OAB files for offline address book '\2010 OAB' but there is no public folder server available. OAB versions prior to version 4 require a public folder server and cannot be generated at this time. Please ensure that a public folder server with a replica of the Offline Address Book system folder is online and mounted, or disable all OAB versions other than version 4.

So have you verified that a 2010 public folder database exist and is mounted? Has the heirarchy replicated? Have you verified email flow between 2003 and 2010? Do you really need v2 and v3 for OAB? I don't believe those clients are supported in Exch 2010 anyway.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

Hi Which Outlook version are in use?Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog

Hi, Please understand that the Outlook clients in Exchange 2003 use the Public Folder to download the OAB, and the legacy Outlook clients in Exchange 2010 also need Public Folder to download the OAB. Thanks Allen

Hello, Please see the link below http://technet.microsoft.com/en-us/library/bb331959(EXCHG.80).aspx The generation server for OAB should have Mailbox Store and Public Folder store mounted. Thanks, Prakash