How can I avoid having to restore users' mailboxes every time they accidentally delete messages from their Deleted Items folder?

Before Microsoft released Outlook 8.03 (the Outlook version that ships with Exchange Server 5.5), Exchange administrators had to restore an entire mailbox to recover one item. Outlook 8.03 and later versions automatically install an extension that adds the Recover Deleted Items command to the Tools menu and the command bar. This command lets users recover items from their Deleted Items folder.

Exchange retains deleted objects in the Information Store for a period that the administrator specifies, and you can recover items during this retention period. You can enable or disable deleted-item retention for Private or Public Information Store objects, a specific mailbox, or a specific public folder, but not for a personal store (PST). For more information about deleted item recovery, see Tony Redmond, "Maintaining Exchange's Information Store," Windows NT Magazine, May 1998.

How can I enable deleted-item recovery?

By default, Exchange Server sets the deleted-item retention period to 0 days for both the Private and the Public Information Stores. You enable deleted item recovery by changing the settings on the Properties page for both the Private Information Store and the Public Information Store. As Screen 1 shows, you can enter in the Deleted item retention time box the number of days you want Exchange to keep deleted items before deleting them permanently. To add another way to recover deleted items, you can select Don't permanently delete items until the store has been backed up. This setting overrides the retention time setting.

How do users retrieve a deleted item from their mailbox?

Users can recover a deleted item by selecting the Deleted Items folder and then the Recover Deleted Items option from the Tools menu. This option reveals a list of items in the deleted items cache. Users select their item from the list and then click the recovery icon to retrieve the item.

How do users retrieve deleted items from a public folder?

To let users recover deleted items from a public folder, you need to enable deleted-item recovery specifically for public folders. In addition to enabling recovery on the Private Information Store, you must enable recovery on the Public Information Store. To enable recovery for the Public Information Store, in Exchange Administrator, select the Public Information Store. On the File menu, click Properties, and change the deleted-item retention settings on the General property page to something other than zero.

When you delete an item in a public folder, Exchange deletes the item in place and hides it; however, the item remains in the public folder for the allotted interval for deleted items. To recover deleted items, users must have full read/write/delete permissions on the public folder. To grant these permissions, set permissions on the folder to Editor. Users can then successfully recover items by selecting the public folder from which the item was deleted and, on the Tools menu in the Outlook client, clicking Recover Deleted Items.

Only one public folder replica can have deleted-item retention enabled. Therefore, if you are using public folder replicas and you want to recover deleted items, you can enable deleted-item retention only on the server that hosts the replica you are connected to.

After I enabled deleted-item retention, users still couldn't retrieve deleted items. What's wrong?

After you change the deleted-item retention settings on the Exchange server, clients currently logged on to the server sometimes can't recover deleted items immediately. If clients can't recover deleted items, you can restart the Outlook or Exchange client, stop and restart the Exchange Information Store service, or wait to let the client register the changes on the server (about 1 hour). The Microsoft Knowledge Base article "XADM: Clients Cannot Recover Items After Item Recovery Enabled" ( kb/articles/q175/2/63.asp) explains this behavior.

I'm worried about the space required to support deleted-item retention. How can I tell how much space message retention is using?

You can view the amount of space message retention is using from Exchange Administrator. Select the Private (or Public) Information Store properties for the server you are administering, display the Properties, and select the Mailbox Resources property page. You can then select View Columns and show the Deleted Items K column. The Deleted Items K column will appear when you view the Mailbox Resources tab.

How does Exchange Server select the best locations for key files (e.g., the Information Store files, the directory, the Message Transfer Agent—MTA—and log files)?

The Exchange Server Performance Optimizer tests the disk subsystem to select the optimal locations for key Exchange Server files. To determine the optimal locations, the Performance Optimizer performs the Sequential (Seq) and Random Access (RA) disk tests, which show which volume (if the server has multiple disk drives) is best suited for log and database files. Screen 2 shows sample results of these two tests.

The sequential write test looks for optimal log file location and simulates Exchange Server Joint Engine Technology (JET) logging activity by creating a 4MB test file that is similar (in flags and structure) to an Exchange Server database log file. The Performance Optimizer writes to this file in the same way Exchange Server does, using synchronous I/O and equivalent buffer and page sizes. During the test, the Performance Optimizer initializes the file with 4MB of data, starts a timer before the first write, and stops the timer when the last write to the file completes. Each write is one page (4KB) in length, and a total of 4MB worth of writes are performed. The Performance Optimizer uses multiple threads to test all disks simultaneously.

The random read/write test simulates database activity and, therefore, is more complex than the sequential write test. Like the sequential write test, the random read/write test uses a 4MB test file and tests all drives simultaneously. However, unlike the sequential test, the random read/write test uses asynchronous I/O for reads and writes.

After analyzing the disk subsystem, the Performance Optimizer uses some additional rules to determine where to locate each type of file on the Exchange server. Performance Optimizer's designers based these rules on common sense and understanding of how Exchange Server uses its various files. Table 1 illustrates some of these rules.

Optimizer uses these guidelines—and some others too complex to discuss in this forum—to rank the available drives (drives can denote physical disks or an array of disks) based on their performance in the sequential and random tests. For example, the best sequential drive is the drive with the lowest sequential access timing that has not been excluded or already assigned. The best random drive has the lowest RA score. By following principles such as separating random from sequential I/O and applying a little intelligence, the Performance Optimizer ensures the optimal Exchange Server configuration.

I would like to run Exchange Administrator on a computer other than the Exchange server. How can I do this?

You can easily administer Exchange Server remotely by installing Exchange Administrator on a workstation that can access the Exchange server over the network. Keep in mind these requirements: First, you must install Exchange Administrator on a workstation that is running Windows NT, either Workstation or Server. Exchange Server 5.5's administration program also requires Service Pack 3 (SP3). This workstation must be a member of an NT domain, either the same domain as the Exchange server you want to administer or a domain that is trusted within your NT security architecture. Also, to run the Exchange Server Setup program, you must be logged on as a user with administrative rights in the NT domain you will administer.

To install Exchange Administrator on the workstation, run the Exchange Server Setup program from the Exchange Server installation CD-ROM. Select the Complete/Custom option, check only Microsoft Exchange Administrator, as Screen 3 shows, and click Continue so Setup will complete the installation. Now you can remotely administer Exchange servers from a networked workstation within NT and Exchange Server security constraints.

I want to let users have multiple Internet email addresses. How do I configure additional addresses for a user?

By default, the System Attendant automatically generates mail addresses (Lotus cc:Mail, Microsoft Mail, X.400, and SMTP) when you create new users. To specify multiple SMTP addresses for a user, you must manually create an additional entry in the E-mail Addresses property page with the following steps.

  1. In Exchange Administrator, highlight the user or other directory object (e.g., a public folder) and then choose File Properties (or double-click the item).
  2. Select the E-mail Addresses tab (Screen 4 shows this display) and choose New to add an entry.
  3. Select the type of email address to be added (Internet Address), and enter the complete address (i.e., on the Internet Address Properties page. Click OK to add the entry.

Be sure that the Address Space entered is a valid configuration for your Exchange Server environment. For example, if you entered, must exist as a valid Address Space for the user to receive mail at this address. In addition, you must configure the necessary entries (i.e., Mail Exchanger and Address records) in your Domain Name System (DNS) and network configuration. For more information about SMTP and DNS, see the following articles in Windows NT Magazine: Mark Minasi, "Untangling Email," April 1998; Spyros Sakellariadis, "Using Exchange Server with SMTP and POP3," June 1998, and "Configuring and Administering DNS," August 1996.