Understanding Recoverable Items

Microsoft Exchange Server 2010 introduces the concept of single item recovery, which was formerly known as dumpster in Exchange 2007. Single item recovery functionality in Exchange 2010 helps you:

• Ensure that all deleted and modified items are preserved.
• Ensure that deleted and modified items can be recovered easily in compliance cases.

This feature helps reduce the risks that are associated with e-mail and other communications by making it easier to keep what is needed to comply with company policy, government regulations, or legal needs. Single item recovery also has the following features:

• All items in a user's Recoverable Items folder are indexed and searchable using the discovery cmdlets.
• All items in the Recoverable Items folder are moved when a move request is performed.
• The Recoverable Items folder is given a quota to help prevent potential denial of service (DOS) attacks by placing large amounts of data in the Recoverable Items folder.

In Exchange 2010, if the single item recovery feature is enabled for a mailbox, even if the end user purges items from their Recoverable Items folder, these items are retained. The Recoverable Items folder contains three sub-folders:

• Deletions   All items that are soft-deleted from the Deleted Items folder within the mailbox are found here. (In Microsoft Office Outlook, you can soft-delete an item with SHIFT+DELETE.) This folder is exposed when accessing the “Recover Deleted Items” feature in Outlook.

• Versions   The original and modified copies of the item are placed here when either legal hold or the single item recovery are enabled. This folder isn't visible to the end user.

• Purges   All items that are hard-deleted are found here, when either legal hold or the single item recovery are enabled. This folder isn't visible to the end user.

  Note

  The items placed in these folders don't count towards the mailbox quota.

While the Purges and Versions sub-folders of the single item recovery feature aren't accessible to the end-user, they are accessible to an administrator or users who are members of the Discovery Management role group. For information about discovery searches, see Create a Discovery Search.

Recoverable Items Mailbox Quota

When an item is moved to the recoverable items folder, its size is deducted from the parent mailbox quota and added to the size of the Recoverable Items folder. The Recoverable Items folder has a configurable soft limit default of 20 GB and a hard limit default of 30 GB. When the Recoverable Items folder reaches the soft and hard limit defaults, the administrator is notified via an event log and Microsoft System Center Operations Manager alert. This alert fires when the Recoverable Items folder reaches the soft and hard limit defaults and then once daily afterward. However, when legal hold is enabled, records management purging of recoverable items data stops. For more information about legal hold, see Understanding Multi-Mailbox Search. For more information about configuring single item recovery, see Configure Single Item Recovery.

The following table summarizes the recoverable items feature.

Single item recovery behavior by feature state

Feature state	Soft-deleted items in Recoverable Items folder	Modified and stored hard-deleted items in Recoverable Items folder	User can purge items from Recoverable Items folder	Messaging Policy and Compliance automatically purges items from Recoverable Items folder
Single item recovery disabled	Yes	No	Yes	Yes; 14 days by default and 120 days for calendar items
Single item recovery enabled	Yes	Yes	No	Yes; 14 days by default and 120 days for calendar items
Legal hold	Yes	Yes	No	No