Quarantine email messages in Office 365
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 (also known as a trasport rule) can be kept for later review.
By default, messages that were filtered for phishing, malware, and mail flow rules are sent to quarantine, while messages that were filtered as spam and bulk mail are sent to the recipients' Junk Email folder. As an admin, you can set up spam filter policies (also known as content filter policies) to send spam and bulk mail messages to quarantine instead. For more information, see Configure your spam filter policies.
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.
High confidence phish messages and messages quarantined by mail flow rule actions are only available in the admin quarantine. Users can access their own phish, spam, and bulk mail messages.
Learn more about working with quarantined messages: