Receive notification for another mailbox?

[stevewy]

If you have a situation where a secretary (for instance) would have
access to their bosses' mailbox, where they could see messages coming
in. Is there a way they could receive a pop-up notification when new
messages arrive in that mailbox, as well as their own? At the
moment, as far as I can see, notifications only pop-up when the
secretary receives new messages in their Inbox.

I see plenty of advice on the web about how to trigger notifications
when mail arrives in a sub-folder of your mailbox - but not when it
arrives in the Inbox of someone else's Mailbox that you have access
to.

Can it be done? Thank you for any help you can give.

Steve