I have set "new mailbox email" and "updated mailbox email" to "mailbox owner + server owner"
Creating a mailbox is fine; it gets sent to both recipients
The "updated mailbox email" event, however, is only sent to the server admin.
This happens when I (as root) edit a user's password for a particular erver.
If the user themselves edit the password, it's even more broken; not emailing anyone, despite notifications on-change being enabled.
Also, when I (as root) set the server owner's password to something new, NO email is sent out to anyone.
Basically lots of tiny bugs with the new email password/updated email password features.