In Exchange 2010 and Exchange Online, we introduced Litigation Hold to allow you to immutably preserve mailbox content to meet long term preservation and eDiscovery requirements. When a mailbox is placed on Litigation Hold, mailbox content is preserved indefinitely.
Placing a mailbox on Litigation Hold You can place a mailbox on Litigation Hold by using the Exchange Administration Center (EAC) or the Shell (set the LitigationHoldEnabled parameter). In Exchange 2010, you can also use the Exchange Management Console (EMC) to do this.
Figure 1: Enabling Litigation Hold for a mailbox using the EAC in Exchange 2013 and Exchange Online
Figure 2: Adding a note and a URL to inform & educate users placed on Litigation Hold
Preserving items for a specified duration To preserve items for a specified period, we added the LitigationHoldDuration parameter to Exchange Online. This helps you meet your compliance needs by preserving all items in a mailbox for the specified duration, calculated from the date the item was created (date received in case of inbound email). For example, if your organization needs to preserve all mailbox data for seven years, you can place all mailboxes on Litigation Hold and set the LitigationHoldDuration to 7 years (in days).
This functionality is also available in Exchange 2013, allowing you to preserve items for a specified duration in your on-premises organization – one example of how developments in Exchange Online benefit Exchange Server on-premises.
In Exchange 2013 and the new Exchange Online, we introduced In-Place Hold, which allows more flexibility in preserving your data. Hold functionality is integrated with In-Place eDiscovery to allow you to search and preserve using a single wizard or a single cmdlet (New-MailboxSearch). You can use the In-Place eDiscovery & Hold wizard or the cmdlet to search for and preserve items matching your query parameters, known as a query-based In-Place Hold, preserve items for a specified period, known as a time-based hold, and also preserve everything indefinitely, which emulates the old Litigation Hold feature. Check out In-Place eDiscovery and In-Place Hold in the New Exchange - Part I and Part II for more info.
If you tried placing a mailbox on Litigation Hold using the EAC or the Shell, both the interfaces displayed an alert message with a recommendation to switch to the new In-Place Hold feature. This recommendation was also reflected in the product documentation.
Figure 3: Warning displayed when using Litigation Hold in the EAC in Exchange 2013
Litigation Hold isn't going away: Since the release of Exchange 2013 and the new Exchange Online, we've received a lot of questions and feedback from you about whether Litigation Hold will be removed. We want to clarify that we do not plan to remove Litigation Hold from Exchange Online or Exchange 2013. We've removed the alert from Exchange Online and in Exchange 2013 SP1. We've also removed the recommendation from Exchange Online and Exchange 2013 documentation.
You can use either hold feature to preserve mailbox data in Exchange 2013 and Exchange Online, based on your preservation needs. Here are some scenarios to help you choose between the two holds.
1 Distribution group is expanded when you run the command. Future changes to the group require running the command again. 2 Distribution groups are expanded only when you create or refresh the In-Place Hold. Future changes to the group require refreshing the search object. 3 Inactive mailboxes is an Exchange Online feature. The linked documentation is being updated to clarify you can also use Litigation Hold to make a mailbox inactive.
Updates - 12/11/2013: Added 'Specify types of items to preserve' row to comparison table. - 12/11/2013: Added 'ItemHoldDuration' parameter to comparison table