Now, when we have threads implemented, it's more important to do this well. Currenlty when a new message arrives: in list mode it is displayed on top of the list, in threads mode the whole list is reloaded.
To make the behaviour consistent and intuitive I propose to add an option "Add recent messages on top of the list". If enabled, new messages will be placed on top as now in list mode. Here I've got a one doubt. In threads mode a message (non-root, which is a part of some thread) also could be placed on top, but there would be a problem with threads counter also this may be not so intuitive. With this option disabled, new messages would be placed in their places. So, e.g. if user has opened let's say a 10th page of the list he will get no new records. Also in threads mode new messages should be placed in their places and if so, some threads may change a placement on the list according to sorting order, but we shouldn't reload the whole list.
What do you think?