>Yes, as nothing has been done yet in regards to that. Before doing something, I am collecting data from members and need some more analysis. So far, it seems we are heading towards a NNTP approach where an unread item remains unread as long as a click is not done on it. The ability to mark all as read would also be applicable. Basically, Outlook has it as well. This, per user, saved on the server, would probably be the best approach. I don't know yet the impact on the process time for each user when reading those messages.

All NNTP readers store information about read/unread messages localy so there's no extra load on server. I think it'll be overkill to store such info per user/message on the UT server. I would suggest that whatever mechanism you've now to ditinguish between read/unread messages for a user should be implemented per user and forum combination.