184.108.40.206.2 Finding the Free/Busy Message
The free/busy messages are stored in a descendant folder of the SCHEDULE+ FREE BUSY folder, under the non-interpersonal messaging subtree of the public folders message store. There MUST be only one free/busy message for each user. A client can read or write free/busy data for users other than the logged-on users. The client MUST find the free/busy message that corresponds to the user before reading or writing information for that user. At the time of publishing, the client determines whether a free/busy message already exists for the user in question before creating one.
To locate the free/busy message that corresponds to a given user, the client does one of the following:
To find the free/busy message of the logged-on user, the client gets the EntryID of the free/busy message. The EntryID of the free/busy message is set in the third binary value of the PidTagFreeBusyEntryIds property (section 220.127.116.11) of the Inbox folder. The EntryID of the free/busy message is used to generate the message ID of the message, as specified in [MS-OXCDATA] section 18.104.22.168. The client uses the message ID of the message to open the message, as specified in [MS-OXCMSG].
To find the free/busy message of another user, the client uses the user's name (full name or part of the name) and performs an ambiguous name resolution (ANR) to get the Address Book object for that user, as specified in [MS-OXOABK] section 22.214.171.124.
If the PidTagFreeBusyEntryIds property does not exist, or if the third binary value of this property is empty, or if the free/busy message is being requested for another user, the subject of the message and the name of the subfolder can be used to find the free/busy message, as specified in sections 126.96.36.199.2.1, 188.8.131.52.2.2, 184.108.40.206.2.3, and 220.127.116.11.2.4.