Barracuda: Login to Shared and Managed Mailbox

Staring May 2, 2023 employees who manage another employee's mailbox or manage a shared mailbox, will need to request a temporary password each time they sign into that mailboxes Barracuda Quarantine Management. The below will guide employees on the process logging into Shared or Managed employee mailboxes in Barracuda.

From the Quarantine notification, click "View Message Log," "Manage Quarantine," or the appropriate link under Actions for the message you are attempting to manage.
Enter the address of the mailbox you are attempting to manage. (make sure it matches the email address shown in the quarantine message)
If you see the below screen, DO NOT click continue, instead click "email a temporary passcode"

Note: A passcode will be emailed to the address of the shared mailbox. The passcode is temporary and valid for only 15 minutes.
Enter the passcode that you received from Barracuda to complete the login to the shared mailbox.
After completing the sign in, you can click "Deliver" or "Allow List" links in the quarantine notification email to perform the related action for those messages.

Source: Temporary Passcode Authentication - Barracuda Email Gateway Defense (barracudanetworks.com)