Explanation/Reference:
Explanation:
In Exchange 2013, you can use In-Place Hold to accomplish the following goals:
Place user mailboxes on hold and preserve mailbox items immutably

Preserve mailbox items deleted by users or automatic deletion processes such as MRM

Use query-based In-Place Hold to search for and retain items matching specified criteria

Preserve items indefinitely or for a specific duration

Place a user on multiple holds for different cases or investigations

Keep In-Place Hold transparent from the user by not having to suspend MRM

Enable In-Place eDiscovery searches of items placed on hold

Note:
When a reasonable expectation of litigation exists, organizations are required to preserve electronically stored information (ESI), including email that's relevant to the case. This expectation often exists before the specifics of the case are known, and preservation is often broad. Organizations may need to preserve all email related to a specific topic or all email for certain individuals.
Failure to preserve email can expose an organization to legal and financial risks such as scrutiny of the organization's records retention and discovery processes, adverse legal judgments, sanctions, or fines.