A notification of new mail could only open the thread, which raises the window; mail that needs no reading had to be archived from parcel. The notification now has an Archive button, Archive all when it sums up several conversations, which archives exactly the threads it names. It invokes an action of the account's own, as opening does, but never raises the window. The desk archives them through a new archive command rather than Done, which also takes off the user labels of the list shown; so it changes the server as e does, and z undoes it.