Hi, Scenario: Brand new Exchange 2007 SP3 UR1 deployment in single windows 2003 Forest / Domain. Exchange is deployed on Windows Server 2003 x64. 4 x CAS / HT Servers, 2 x Public Folder Mailbox Servers (No Mailbox Stores Present), 2 x Mailbox Server roles (No Public Folder Stores Present). Added replicas of system folders from PF server 1 to PF Server 2. Added single Mailbox database to Mailbox Only role server 1, and set Default Public Folder store to be Public Folder Server 1. Application event logs clean on both Public Folder only Servers. Application event log on Mailbox Server 1 hosting single mailbox database reports Error from Source: MSExchangeFBPublish, EventID: 8197. Description: Error initializing session for virtual machine SERVER. The error number is 0x80004005. Make sure Microsoft Exchange Store is running. Also, make sure that there is a valid public folder database on the Exchange Server. Now, there isn't a valid public folder database on the Mailbox Database role server, by design, since we want the other dedicated Public Folder Servers to host the PF databases. Having added Public Folder Replicas to each PF server for the Free / Busy System Folder, the error is still produced every 25 minutes, even after restarting the Info Store and System Attendant on the Mailbox database-only server. I can see the hierarchy from both PF servers and can perform Get-PublicFolderStatistics with results on both, so enumeration seems to be just fine. I have created a mailbox on the Mailbox role-only server and setup some appointments in Outlook 2003 Online mode, and updated the Free / Busy publishing settings in the client to be every 2 minutes to try and populate the folder, in case that was the problem, but this does not seem to have altered anything as yet. Since this is a pretty much 'out of the box' implementation, is there anything I'm missing here? How can I tell what the Mailbox role-only server is looking for, when it is reporting the error regarding FB Publish, or indeed, does anyone know how to resolve this for a green-field implementation? Thanks in advance.

OK, to follow on from this, I am also unable to generate the OAB files for version 2,3 and 4 Outlook. App Event Logged. Source: MSExchangeSA, Category: OAL Generator, Event ID: 9386 and 9399 are logged after performing an 'Update Now' on the OAB. The PF Database is definitely mounted, and the Web-based OAB distribution files are being populated just fine, it's just the Public Folder elements of anything to do with OAB, Free / Busy. Am I having these issues because the 'System Attendant Mailbox' is not present on either of the Public Folder servers, due to it having no Mailbox Database present (intentional), only a Public Folder database? Although http://technet.microsoft.com/en-us/library/aa997314(EXCHG.65).aspx is not related to Exchange 2007, it contains a fair bit about the roles of the SA Mailbox, and I am wondering if the SA Mailbox is stil required to handle all of the legacy public folder operations, and maybe that's why I'm experiencing these issues. Any thoughts much appreciated.

OK, answered my own thread again. AND THE SOLUTION IS: You absolutely require a Mailbox Database to be present on the server hosting the Public Folders, if you want to support legacy System Public Folders and OAB V2, 3 and 4 Distribution. The 'System Attendant Mailbox' must be present and set as the HOMEMDB value on the System Attendant, which it will be as long as a valid mailbox database exists. Created a new Storage Group and Mailbox Database on the Public Folder server, waited 5 minutes or so for the Information Store and System Attendant Services to sort themselves out, and all fixed. Running an 'Update Now' on the Offline Address Book Generation Server no longer produces the 9386 and 9399 errors in the Application Event Log. Indeed, no events are logged at all if the process goes well, at 'Lowest' Diagnostic Logging level. Checking in the Public Folder Management Console, we now have the 'OAB Version 2', 3 and 4 folders present as desired and the Outlook 2003 client can successfully download the OAB. So, DON'T delete your mailbox database, EVEN if you only want to host public folders for legacy client purposes, as the System Attendant will not be happy at all. Regards