I don't know if this is possible or not, and the ESO forum site gives no information on what forum site software it's based on. In any case, my suggestion is as follows: instead of the forum site sending us emails for every single reply to a thread that we've previously read or favourited, how about just sending 1 email for the first unread reply ? The site can then put any further reply notification emails for that thread on hold until the user visits the thread again. We'd all be grateful for this, as we wouldn't be flooded with emails for threads that we've read that turned out to be very popular.
PC(Steam) / EU / play from Melbourne, Australia / avg ping 390