You have an Exchange Server organization. The organization contains servers that have Exchange
Server 2010 and Exchange Server 2016 installed. You establish a hybrid deployment between
Exchange Server and Microsoft Office 365. Some users have on-premises mailboxes and personal
archives in Exchange Online. You discover that you are unable to use In-Place eDiscovery to
search user mailboxes and Exchange Online Archiving archives concurrently. You need to
recommend a solution to ensure that In-Place eDiscovery can search the mailboxes and the
personal archives concurrently. What should you include in the recommendation?
A.
Auth authentication
B.
an organization relationship
C.
a retention policy
D.
the Mailbox Replication service (MRS)
I agree.
To successfully perform cross-premises eDiscovery searches in an Exchange 2016 hybrid organization, you will have to configure OAuth (Open Authorization) authentication between your Exchange on-premises and Exchange Online organizations so that you can use In-Place eDiscovery to search on-premises and cloud-based mailboxes. OAuth authentication is a server-to-server authentication protocol that allows applications to authenticate to each other.
OAuth authentication supports the following eDiscovery scenarios in an Exchange hybrid deployment:
Search on-premises mailboxes that use Exchange Online Archiving for cloud-based archive mailboxes.
Search on-premises and cloud-based mailboxes in the same eDiscovery search.
Source: https://technet.microsoft.com/en-us/library/dd298021(v=exchg.160).aspx