From Microsoft Corporation
MC211521, Stay Informed, Published date: Apr 30, 2020
We are adding support for end-user spam notifications for shared mailboxes.
This message is associated with Microsoft 365 Roadmap ID 63553When this will happen
We’ll be rolling this out in mid-May.How this affects your organization
Before this change, any User who had access to a shared mailbox could only perform quarantine actions by logging in through the security and compliance center.
With this change, any user who has access to a shared mailbox will be able to check/release quarantined mails through email spam notification.