EOP- Quarantine- Access to shared or other person quarantine

Hi RobertS00 

Thank you for contacting Microsoft Tech Community. 

If I understand you correctly, you want to know if users can actually view and release quarantined messages from a shared mailbox. 

There are two different methods to access quarantined messages that were sent to a shared mailbox:

• If the following statements are all true:
  • An admin has configured quarantine policies to allow quarantine notifications (formerly known as end-user spam notifications).
  • The user has access to quarantine notifications of the shared mailbox.
  • The user has Full Access permissions to the shared mailbox (directly or via a security group).

See View and release quarantined messages from shared mailboxes - Office 365 | Microsoft Learn

Note: This would work when the user has Full Access permissions. User can click the Review link in a quarantine message and see the email, or go to 'https://security.microsoft.com/quarantine'  and use the Filter to update the Recipient Address to the shared mailbox.

Meanwhile, you just need the full access permission to a mailbox to be able to access and manage quarantined messages sent to their mailbox. Please let me know if this helps.

I await your kind response!