Hello everyone,below is an extract from a great article
Public Folders, Offline Address Book and Free/BusyOutlook 2003 uses the Public Folders free/busy messages to determine availability in the Calendar and as the source for Offline Address Book synchronization. If Public Folders are not configured during Exchange Server 2010 setup, Offline Address Book and Free/Busy will not be available to Outlook 2003 users. These users will encounter connection errors.
If free/busy Public Folders folder is not replicated to Exchange Server 2010, users will encounter the following:
Users who use Outlook 2003 cannot publish their free/busy data in Exchange Server 2010 or in Exchange Server 2007http://support.microsoft.com/kb/945602If clients inside the organization or connected via VPN/RAS, and the organization uses a Proxy server, the Client Access Server should be listed in the "Bypass proxy server for local addresses" configuration.
Error message when Outlook synchronizes an offline address book with Exchange Server 2007 and Exchange Server 2010: "0x8004010F"http://support.microsoft.com/kb/939765Also, if there are missing address book list objects or missing or incorrect address lists, the following may occur:
An error occurs when you try to synchronize the offline address list on an Exchange Server server while you are using Outlook 2003: "0x8004010F" http://support.microsoft.com/kb/905813
Opening Additional MailboxesDelegate Access issues, opening other user's folders or mailboxes are a common operation in the enterprise. Outlook 2003 users may encounter issues, if the environment is not properly prepared for their use:
Office Outlook 2003 does not connect to two or more additional mailboxes in a mixed Exchange Server 2007 and Exchange Server 2010 environment http://support.microsoft.com/kb/978777
An error occurs when an Exchange server 2003 user tries to open more than one delegate mailboxes of Exchange Server 2010 in Outlook 2003 http://support.microsoft.com/kb/979690Enjoy!