I have server 2010 running with 2003 clients. We used to be able to view each others calendars via shared calendars within outlook. Now it will sometimes show you the calendar and sometimes it comes up with a error - the connection to the microsoft exchange server is unavailable - outlook must be online or connected to complete this action - if you keep pressing ok it eventually shows you the calendar, then the next day it wont and the next day it will.

What I would recommend (long term plan, or even start now) is to deploy 2010 OLK client for the end users. This way you can move away from the free/busy PF requirement and rely on the availabilty service.Sukh

Hi Sadie Jane, Maybe http://blogs.technet.com/b/kovaij/archive/2011/02/01/outlook-2003-error-prompts-while-opening-additional-calendars-in-exchange-2010.aspx will help you to figure out what's going on there. Timo

Hi Sadie Jane, Maybe http://blogs.technet.com/b/kovaij/archive/2011/02/01/outlook-2003-error-prompts-while-opening-additional-calendars-in-exchange-2010.aspx will help you to figure out what's going on there. Timo

Hi Sadie Jane, Is there any update on this thread? Thanks, Simon Wu Exchange Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com