Hi All,We have 3 domains in our environment - UK.domain.com, US.domain.com, and Japan.domain.com. Each domain is a seperate Admin group and Routing group in Exchange 2003.I'm a relative newbie to Public Folders, so please go easy :)I've noticed on one of our Routing Group Connectors that the size of the EDB file has increased substantially....I checked, and the volume is caused by;OAB v2OAB v3aOAB v4Does anyone know what has caused this? Surely we should only have one version of the OAB? How can I check which is currently being used?Secondly, as an aside, I notice that each server also has Schedule+Free Busy Information for the other domains in the PF Store. Is this as per design? Does each different server's Public Folder store have a Schedule+Free busy folder...and what does this represent? The Free/ Busy time of everyone in the Exchange org?Any help appreciated.

~ Well, it depends on the Exchange and Outlook version you use in your environment. Check below article for compatibility of OAB versions and Outlook/Exchange. Deployment Scenarios for Outlook 2003 http://technet.microsoft.com/en-us/library/aa997008(EXCHG.65).aspx ~ Yes, free/busy information stored based on Admin Groups where user mailbox created first time so it is available for all admin groups. I would suggest you to don't touch system public folders in non mapi tree like OAB, Free/Busy etc... BTW, which edb file is getting increased? Public folder or mailbox database? If it is public folder, you can get content report of your PF jungle with PFDavAdmin and find which mapi public folder is getting increased. PFDAVAdmin Content Report - First step to explore the jungle of your public folders http://msexchangeteam.com/archive/2006/02/01/418566.aspxAmit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Hi Amit,Thanks for replying.Free/Busy: I am still trying to get my head round this :) Ok, so on the server I see the Schedule+Free Busy Info for all three domains as three different PF's. In fact, I can see this on most of my servers. So, would I be correct in saying that each Exchange server holds the Free/Busy Information for everyone in the Exchange org. Where is this set? Can we restrict this so that only Free/Busy information for one other domain is held? For instance, it would be useful for the US and UK domains to hold Free/Busy information for each other's users, but there is not much collaboration with Japan, so there is no need to UK Exchange servers to hold Free/Busy info about Japan users?EDB file: Yep, it's the Public Folder database, specifically the OAB books. I assume this is just a usual increase caused by an increasing number of mail enabled users? Nothing to worry about? Thanks again.

How frequently users are using availability of other users in your organization and the network speed between these domains comes into picture... Check below couple of articles for best practices of Free/Busy placement and generation process in your environment and you can set replica of Free/Busy according to their location. Exchange Public Folder Best Practices: Implementing Replication -http://technet.microsoft.com/en-us/library/bb123619(EXCHG.65).aspx Free Busy generation process -http://msexchangeteam.com/archive/2006/08/04/428597.aspx OAB: Approximate OAB size is 1MB per 1,000 users you can consider plus certificates if you are using and normal size is 3MB to 700MB and also depend on number of users, DL and the attributes you populate in it. Check below KB for further detail. Administering the offline address book in Outlook 2003 and Outlook 2007 -http://support.microsoft.com/kb/841273Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Well, Amit has answered all questions, I can only share a little more resources to you. Please see Server Per Site Topology section in Supported Topologies, which would be the good option for your Free/Busy replication topology