Outlook freebusy information

How Outlook 2007 fetches Freebusy in Exchange 2007 environment:

Outlook 2007 runs against Availability Service Web Service and relies on the Autodiscover Service to find the Availability URL to view the Freebusy information on Exchange 2007. So in regards we can check the requests going to the CAS server. Outlook 2007 issues may be related to Autodiscover/Availability/CAS(IIS virual directories…speaking on larger scale. )
Information visible on OWA , not visible on Outlook 2007: Issue is more likely with Autodiscover.

Outlook versions earlier than Outlook 2007 uses LegacyExchangeDN attribute to view the freebusy information.
LegacyExchangeDN attribute is also used by Outlook clients’ in Exchange 2007 to delegate access to folders.
Outlook 2007 =>CAS local=>CAS Remote AG=>Ex2007
Outlook 2007=>CAS local=>Public Folder server by http://server/public/?Cmd=freebusy>

+CAS gets requests to get free/busy from remote AG user, CAS will choose home PF server as attendee’s home server. If there is no PF replica CAS will choose another PF randomly.
+If CAS can not return the information , it adds the server to badserver list and will connect to the good server for further information.

Data stored in LocalFreebusy folder:
Free/busy publishing settings
Delegate configuration
Direct booking options

Errors when Local Freebusy is Corrupt:
Unable to save free/busy information
Unable to clean your local free/busy information.
The Delegates settings were not saved correctly. Unable to activate free/busy information.
The Delegates settings were not saved correctly. Unable to activate send-on-behalf-of list. You do not have sufficient permission to perform this operation on this object.
Can't open this item. Unable to open the free/busy information (EventID: 25)
Ref KB:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;958443

What is PR_FREEBUSY_ENTRYIDS?
The PR_FREEBUSY_ENTRYIDS is a pointer to the LocalFreeBusy message stored in the Freebusy Data folder of the mailbox. During the mailbox move the pointer becomes unreadable by Outlook.

For deletion of this entry via mfcmapi tool refer to the below post:
http://outlook2007troubleshooting.blogspot.com/2011/06/delete-freebusy-via-mfcmapi.html

+Check if these users have been migrated from a different admin group or server. If so then check their LegacyExchangeDN value using ADSIEdit and surfing through the user attributes.The LegacyExchageDN value should be correct. The LegacyExchangeDN value contains the same name of the Administrative Group.