Microsoft Exchange Server 2007: Tony Redmond's Guide to Successful Implementation

8.8 Free and busy 853

Chapter 8

Items” feature. Alternatively, you could also restore a copy of the mailbox

database to another server and recover the data from that copy.

8.7.1 Auditing

Somewhat surprisingly, Exchange does not provide a way to audit the use of

the

Export-Mailbox command, so it is possible for an administrator to

select the mailbox of someone important (or interesting) and run a job to

export data without leaving any trace that they cannot erase quickly after-

wards. Apart from the log files that Exchange creates for every

Export-

Mailbox

operation, the only other trace that an administrator has accessed

someone’s mailbox is in event 1006 logged by the Exchange Migration

component (Figure 8.49). For this reason, it is important that you set out

clear guidelines as to when an administrator can use the

Export-Mailbox

command in the same way that guidelines exist to permit other administra-

tor access to user mailboxes.

8.8 Free and busy

Free and busy data is the mechanism used by Exchange and its clients to

track the availability of users for meetings. All versions of Exchange prior

Figure 8.49

Export mailbox

event

854 8.8 Free and busy

to Exchange 2007 store the data used by clients to calculate when users

are available in a public folder, but Exchange 2007 introduces the new

Availability Service to replace the need to hold data in a public folder in

favor of direct publication of free and busy data by Outlook 2007 clients

as properties of user mailboxes. However, it is going to take some time

before any organization is able to deploy Exchange 2007 everywhere, so

we will have to deal with the public folder-based implementation for

quite some time to come.

Outlook is responsible for updating the data in the public folder and

does so according to user-specific options as shown in Figure 8.50. The

default is for Outlook to connect and update free and busy data every 15

minutes and to publish 2 months of availability data. In other words, if

every user in the organization uses the default publication options, you will

not be able to see the availability of another user’s calendar past the next 2

months, even if they have scheduled meetings and other appointments past

that time. You can publish a maximum of 36 months free and busy data

and update the server as often as every minute.

Free and busy data describes when a user is busy over a period of time

but does not hold any other information, such as whether they are at a

meeting or have a personal appointment, the location, or any other indica-

tion of why they might be busy. Thus, when you view another user’s calen-

dar and see that they are busy between 10

AM and 5PM, the time might be

taken up by one long appointment or occupied by several shorter meetings.

In addition, the items in the other user’s calendars may have different status

such as busy or tentative. Essentially, Exchange treats any slot that a user

creates in their calendar as busy and any that is vacant as free.

Figure 8.50

Outlook free/busy

publication options