The following topics provide information about the hosted quarantine for both Exchange Online and Exchange Online Protection (EOP) admins and end users:
Quarantine FAQ - Provides general questions and answers about the quarantine for both admins and end users
Find and release quarantined messages as an administrator - Describes how admins can find and release any message that resides in the quarantine in the Exchange admin center (EAC), and optionally report it as a false positive (not junk) message to Microsoft.
Find and Release Quarantined Messages (End Users) - Describes how end users can find and release their own spam-quarantined messages in the spam quarantine user interface, and report them as not junk to Microsoft.
In order to access the end user spam quarantine, end users must have a valid Office 365 user ID and password. EOP customers protecting on-premises mailboxes must be valid email users created via directory synchronization or the EAC. For more information about managing users, EOP admins can refer to Manage mail users in EOP. For EOP standalone customers, we recommend using directory synchronization and enabling Directory Based Edge Blocking; for more information, see Use Directory Based Edge Blocking to Reject Messages Sent to Invalid Recipients.