Exchange 2010 Discovery: Modify the maximum number of mailboxes searched at a time
In Exchange 2010, you can use Multi-Mailbox Search to search mailboxes for e-Discovery or similar purposes. To preserve data in user mailboxes and protect its integrity, you can place a mailbox on Litigation Hold (also known as legal hold). This prevents mailbox items from being purged from the Store, without impacting user workflow. Additionally, when a mailbox is on litigation hold, a process known as copy-on-write (yes, COW) preserves a copy of the original item when a modification is made to certain item properties.
Read the complete article at https://blogs.technet.com/b/exchange/archive/2011/05/25/exchange-2010-discovery-modify-the-maximum-number-of-mailboxes-searched-at-a-time.aspx
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