The Exchange store is not involved in this process, with the exception of a system public folder in a public folder store that is used for storing and publishing data.
Outlook first gets a referral from the mailbox server for the associated Free/Busy public folder.
Calendar Connector requires permissions to read and create items in the Free/Busy system folder.
In the properties of the Free/Busy folder for your local administrative group, select the Permissions tab, and then click Client Permissions.
This is represented by a stream of numbers on the Free/Busy server (a public folder server with public folders containing replicas of one or more of the Free/Busy site folders).
One representation is 002222000033333333, where each number represents X minutes of increment (as specified in the request, with 6 minutes being the lowest granularity).
Outlook Web Access and Outlook Mobile Access clients also generate free/busy items as calendar items are saved.
From there, Outlook Web Access or Outlook Mobile Access sends the message through collaboration data object (CDO) and Web DAV to System Attendant, which is responsible for additional processing the message and publishing to the server that is running Exchange Server.
Calendar Connector must be installed on a server that is running Exchange Server 2003 with an instance of the Free/Busy public folder for the local administrative group.Each group represents one of the busy classifications (busy, tentative, or OOF), and each item in the group represents one month of data.The array itself is a group of pairs, in which each pair is the number of minutes into the month the busy period starts and ends, time-zone-adjusted to the International Date Line.After the server is located, properties on the user object in Active Directory are used to find the free/busy message in the public folder.Each free/busy message is a representation of the days and times that are busy and the days and times that are not busy for a single person or resource.