I have a coexistence of 2003/2007 for a short time now.. maybe another week.. I noticed that under Organization Configuration.. Mailbox.. Offline Address Book tab.. Double click Default Offline Address list.. Properties.. Distribution tab.. the enable web-based distribution is greyed out.. Is this normal.. should I have this box checked, i'm not totally sure what its purpose is either.. Thanks

Did you configure your Exchange 2007 server as the Offline Addressbook Server? There must be at least one Exchange 2007 CAS server in your environment. Deli

Hi, I have the same problem. In my organization I have one server exchange 2000 e one server 2007 with Mailbox, CAS and HUB server enable. I'm performing a transition to exchange 2007. If I create a new OAB the web based distribution option isenable. Can I enable the default OAB to? Thank you Simone Reale

Hi people!! I was having this problem yesterday but I can solve it.. It is simplier... When you have Outlook 2003 you will be using the OAB based on Public folders and when you are using Outlook 2007 you will need to use web-based distribution.. until here ok... So, you need to enable the public folder replication in the Exchange 2003 to 2010 or 2007. ok, now, you will need to change the OAB generator for the Exchange 2007 to be the mandatory OAB's generator. In 2010 you have an option for changing it in the EMC, I don't remember in Exchange 2007 but certainly there is a powershell cmdlet for it. You need to verify in the database's properties what is the OAB that is assigned to it. Ok, after the OAB's generator change you need to verify in the mailbox if the OAB is being generated. So you need to explore the IIS OAB virtual directory, it will have a lot of files. Ok after it, you need to go until the CAS server and to execute an update-filedistributionservice, thus the CAS will be copyng the OAB from the mbx to the CAS. you need to understand that the OAB is generated by the Mbx but is published by the CAS... ok? sorry my english...see you, MCSA, MCTS 7, MCITP SA, MCITP EA, MCITP Messaging *Best Regards Don't forget to mark it as answer if it helps

RPeluffo is correct. You need to ensure Exchange 2007 or 2010 is the OAB generation server. You also need to ensure there is a OAB replica on the Exchange 2010 server if using public folders for OAB distribution, which is the only way to support Outlook 2003 users. Mike Crowley | MVP My Blog -- Planet Technologies