What you can do is go to your "Manage Subscriptions" page in your member center and any subscribed threads with new responses will be at the top of
the list.
.
This feature used to exist, but it soon turned into a nightmare for members (and staff on the receiving end of heated rants) when they would receive
e-mails into the dozens and even hundreds stating there was a new reply to a thread they subscribed to.
Factor that by the number of different subscribed threads and that can become one hell of an inbox!