You can set up quarantine for incoming email messages in Office 365 where messages that have been filtered as spam, bulk mail, phishing mail, mail that contains malware, and mail that matched a specified mail flow rule can be kept for later review.
By default, filtered messages are sent to the recipients' Junk Email folder, except for phishing mail and mail that contains malware which are sent to quarantine by default. As an admin, you can set up content filter policies to send all filtered messages to quarantine instead. The different actions that you can take 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: