Understanding Recoverable Items

[Cette rubrique est en cours de rédaction.]

Dernière rubrique modifiée : 2009-10-13

Exchange 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 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 (in Outlook, Shift+Delete) from the Deleted Items folder within the mailbox are found here. This folder is what 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 is not 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 is not visible to the end user.

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

While the Purges and Versions 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 Gestion de la détection role group. For information about discovery searches, see Créer une détection.

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 recoverable items folder size. The recoverable items folder has a configurable soft limit default of 20 GB and a hard limit at 30GB. When it reaches that size, the administrator is notified via an event log and MOM alert. This alert fires when the recoverable items folder reaches the limit and once daily afterward. However, when legal hold is enabled, records management purging of recoverable items data stops. For more information about legal hold, see Présentation de la recherche dans plusieurs boîtes aux lettres. For more information about configuring single item recovery, see Configurer la récupération d'élément unique.

The following table summarizes the recoverable items feature.

Single Items Recovery Feature

Feature State	Soft-deleted items in recoverable items folder	Modified and store 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