May or may not be desirable, but I've noticed that with the influx of players and increase in server activity that the letters forum scrolls quite a lot more quickly now.
It would enable DM's to browse a more concise list of DM addressed letters at a glance, and prevent players from needing (or feeling the need) to bump their DM addressed letters until they are replied to.
I concur!
This does seem like a good idea to me too. Especially for busy DM's.
It probably makes it more bothersome for us, having to separate DM / PC letters fully and what not. We can find DM letters with fairly little trouble. It's why we tell folks to mark them [DM] Or something and we can just search for it.
I can safely say that being put in the position of definitely needing to answer the many letters of the world, instead of at least having the opportunity that a PC might be able to get involved and respond, combined with Paha's point, is not in our best interests.