When you synchronize and then work offline or restart offline, the following error message appears when you press F9 to reconnect for another synchronization and then click Cancel in the network logon dialog box:
Task "Microsoft Exchange Server" reported error (0x8004011D): "The server is not available. Contact your administrator if this condition persists."
To work around this behavior if your next attempt to synchronize does not prompt for logon, restart Microsoft Outlook offline, and then press F9 to synchronize.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.