Windows 7 / Getting Started

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Deleted Item Recovery and Dumpster 2.0

In previous releases of Exchange Server, as items were deleted they were put into the Deleted Items folder until the folder was emptied. This gives the end user the opportunity to review and recover the items before they are permanently deleted. When the Deleted Items folder is emptied, the messages are specially flagged to be included in the dumpster and essentially removed from the mailbox. If the end user needs the information after emptying the deleted items folder, the user can use the Recover Deleted Items option to retrieve the deleted data for the duration of the deleted items retention set for the mailbox. The items in the dumpster exist for the duration of the deleted item retention policy or until the items are manually deleted from the dumpster. The messages in the dumpster are not searchable; there is no way to enforce quotas on the deleted items and there is no method to block end users from manually purging the data from the dumpster.

Although the dumpster feature is invaluable in being able to recover deleted information by greatly reducing or eliminating the need for database restores and performing MAPI- based mailbox (brick-level) backups, these shortcomings limit the usefulness of the feature. In Exchange Server 2010, investments have been made to improve this feature.

Note: In versions of Outlook earlier than Microsoft Office Outlook 2007, connected to Exchange Server 5.5 and later, the Recover Deleted Items option is only shown for the Deleted Items folder. This often leads some to believe that using Shift+Delete to remove messages permanently purges the information; however, the deleted information actually still exists in the dumpster for the folder containing the original message. The Recover Deleted Items option can be enabled in Outlook by setting the DumpsterAlwaysOn registry key.

Exchange Server 2010 introduces a new version of the dumpster, sometimes referred to as Dumpster 2.0. Unlike in the previous iteration of the dumpster where the items were flagged and hidden, Dumpster 2.0 is implemented as a non-IPM folder called Recoverable Items in each user's mailbox. Non-IPM folders do not show up as standard folders within the Outlook or Outlook Web App. This folder has three subfolders: Deletions, Versions, and Purges. Each is used to provide enhanced functionality to Dumpster 2.0.

Deletions Folder

The items that are moved to the Deletions folder are items that are soft-deleted and that would have ended up in the per-folder dumpster in previous versions of Exchange Server. To ensure that this works with Outlook 2003 and Outlook 2007, which only understands how the dumpster works in previous versions of Exchange, the RPC Client Access server will translate any calls made to the dumpster into calls into the Recoverable Items\Deletions folder. The Deletions folder data is subject to the Deleted item rendition time set on the database or on the mailbox.

Using a non-IPM folder to store deleted items allows the following:

• Deleted information can be stored per mailbox instead of per folder.
• Deleted information can be indexed and searched.
• Deleted information can be moved when the mailbox is moved to another database.

Note: In Exchange Server 2010, each mailbox can also have an associated online archive mailbox, which has a separate Recoverable Items\Deletions folder to store data deleted from the online archive mailbox.

Purges Folder

The Purges subfolder is used when Single Item Recovery is enabled on the mailbox-if Single Item Recovery isn't enabled, deleted items are moved into the Deletions folder. If items are removed manually from the Deletions folder (when Single Item Recovery is enabled) before the deleted item retention time has transpired, the messages are moved into the Purges folder for the duration of deleted item retention. The Purges folder cannot be accessed by end users and would be used by the administrator to recover deleted data; therefore, this feature solves one of the deficiencies of previous versions of Exchange where end users could manually remove deleted items allowing potentially incriminating information to be deleted, if other measures were not employed.

Note: R egardless of whether Single Item Recovery is enabled, calendar items are maintained in the Recoverable Items folder structure for 120 days. However, a legal hold can enable longer-term data preservation to disable the expiration of the items.

Versions Folder

The Versions subfolder is used when either Single Item Recovery or Litigation Hold is enabled. Anytime a message in the enabled mailbox is modified the original message is copied to the Versions subfolder. Each version is kept and can be searched by a user assigned the Discovery Management role. This is invaluable in finding e-mail messages that might have been modified to hide or alter the original content of the message. Messages stored in the Drafts folder are exempt from this behavior to reduce the amount of unnecessary data in the folder.

The prospect of capturing the versions of modified e-mail messages further reduces the need for restores resulting from messages being modified.

The Dumpster 2.0 configuration options are summarized in Table-4.

Table-4 Dumpster 2.0 Configuration Options

Feature State	deleted items kept in dumpster 2.0	versions and hard - deleted items kept in dumpster 2.0	User can purge items from dumpster	automatically purge dumpster items
Single Item Recovery disabled	Yes	No	Yes	Yes, using deleted item retention for e-mail and 120 days for calendar items
Single Item Recovery enabled	Yes	Yes	No	Yes, using deleted item retention for e-mail and 120 days for calendar items
Litigation Hold enabled	Yes	Yes	No	No