Our forums haven't been sending out email notifications on updated subscribed threads for a long time. Many of you have already noticed that, and have been in contact with us about the issue. We're terribly ashamed about the fact that it has been broken for so long, and thank each and everyone of you showing concern over the feature.
We have previously taken looks at what could be wrong with that on several occasions. But each time we have been left stumped, and we had no idea what could be wrong with it. Each time we have needed to give up on the matter, as other deadlines have become ever more pressing.
A few weeks ago, we decided that this problem cannot be left unfixed for any longer, and decided to set aside any other pressing matters, in order to get this fixed once and for all. After a lot of investigation, we finally have found the problem and been able to fix it. From now on, you should be once again able to subscribe to a thread, thus getting email notifications about updates in a thread. You can subscribe by pressing the "Subscribe" above the first post in a thread, if you're logged in.
During investigation, we noticed that for some strange reasons, the subscription data has been corrupted: the threads you once were subscribed to might have become unsubscribed by themselves. We are unable to recover this, and that data is unfortunately lost forever. But: If you wish, you can go back to threads and re-subscribe to them. Any threads you subscribe to from now on, should remain so.
We feel terribly bad that this fix took so long to be fixed, and it pains us that some data has been lost during all this. But we're also relieved that this issue now seems to be fixed, and everything should work as before, once again.
If you notice some weird behavior, please, don't hesitate in letting us know.