Question : Exchange Server unavailable

Running SBS 2000 with all service packs and hot fixes.  Running Windows 2000 Professional on workstation and Office XP with all service packs and hot fixes.  When the client launches Outlook the following error message appears: "Your Microsoft Exchange Server is Unavailable."  The client has three options: "Retry, Work Offiline, Cancel".  When the client clicks on "Retry" they connect to the exchange server.  There are about 20 clients and this is only a problem with four or five of them. Any ideas or suggestions

Answer : Exchange Server unavailable

did you try to deleting and re-creating  outlook profiles on client pcs?