Litigation Hold Can Max Out Recoverable Items 30 GB Limit

In MS Exchange, if you place a litigation hold on mailboxes to preserve email messages for a long period of time, keep in mind that modified or deleted Outlook items will be preserved in the Recoverable Items folder. This may cause the data stored in this folder to exceed its default maximum size of 30 GB.

Have the Exchange admin monitor the folder size, or sufficiently increase the default to deal with the accumulated data.

Emails Purged From Outlook May Still Exist

After an email is deleted from the Deleted Items folder, or removed from the Inbox with SHIFT + DELETE, the email will be sent to the Deletions subfolder of the Recoverable Items Folder. The Recoverable Items Folder is not visible to the user. Each user's profile contains a deleted item retention period set by the admin. The default is 14 days. So, in most cases emails can be recovered for up to 14 days after a user has tried to delete them. The 'Recover Deleted Items' command is on the Folder tab of Outlook.

If an email is purged from the Recovered Deleted Items folder, or if the set retention period elapses, it is sent to the Purges subfolder of the Recoverable Items Folder. However, the email will not be removed from the Purges folder until the mailbox assistant processes the folder. A post on Microsoft's official site for Exchange states that: "You can configure the Managed Folder Assistant to process all mailboxes on a Mailbox server within a certain period (known as a work cycle). The work cycle is set to one day by default."

In-Place eDiscovery In Microsoft Exchange

Microsoft Exchange makes possible in place preservation of email messages. The archiving of relevant emails involves significant costs because of the need for a user to manage the copying or because of the need to purchase software to implement the hold on the email messages.

The LitigationHoldEnabled property of a mailbox will prevent any item in a mailbox from being removed.

The alternate 'in-place hold' will only direct the retention of emails which come up in a search query. A single mailbox can have multiple in-place holds, but no more than 500 search terms can be used.

Using more than 500 terms in a query will cause all content in the mailbox to be preserved. The LitigationHoldEnable property is either set or not. Either type of hold can be set to remain for a specific time period.

Searches can be run on the messages that are subject to in-place holds. While a hold is in place a user will retain the same rights to delete emails. The admin has the option of informing the user that the mailbox is subject to a hold.

Both types of holds use the Recoverable Items folder to preserve emails. So even when SHIFT + DELETE is used or emails are deleted from the Deleted Items folder, the emails are transferred to the Recoverable Items folder. The recoverable items folder is not visible to users. Note that a user does have the option to recover deleted items on the folder tab.