You can set up a quarantine for incoming email messages in Office 365 where incoming email messages that have been filtered as spam, bulk, or phishing mail can be kept for later review.
Note: We’re rolling out Quarantine for the Security & Compliance Center, so you might not see it yet. If that's the case, use Quarantine in the Exchange Admin Center instead. See Quarantine content on Technet
By default, filtered messages are sent to the recipients' Junk Email folder, except for phishing mail which is sent to the quarantine by default. As an admin, you can set up content filter policies to send all filtered messages to the quarantine instead. The different actions that can be taken for content-filtered messages depend on the spam filter policies you've defined.
Both users and admins can work with quarantined messages. Users can work with just their own filtered messages in quarantine. Admins can search for and manage quarantined messages for all users.
Learn more about working with quarantined messages: