For internal reasons (to do with the way Mercury manages the list files) it's not a trivial change to sort the subscriber list. It's a reasonably common request, but implementing it will take quite a bit of effort.

Cheers!

-- David --

Not sure whether this made it thru to 4.5, but if not put it in for v5:

In the list view for subscribers, clicking on the list header sorts it (and clicking again reverse sorts it).