I see no settings in drupal that allows subscription to a particular thread whenever it is updated
Subscription functionality isn't built in to the Drupal forum module. Drupal.org tries to keep overhead low so the "subscription" contrib module or other contrib solutions haven't been implemented here.
The "Tracker" is helpful. Go to: http://drupal.org/tracker/ will get you to a list of threads where you have made contributions. Substitute your user number in the <>. This leads to the inelegant practice of folks leaving a comment in a thread that simply says "subscribing" in order that the thread gets picked up in their tracker page. Not ideal.
Note that the issue queue section of the Drupal.org section, supported by a different module does support email subscriptions.
Here is the page to sign-up to subscribe, on a per module basis, for the issue queue.http://drupal.org/project/issues/subscribe-mail
Something you may not be aware of is that the "issue" queues have "support request" as an issue category. So the issue queue is not just for bug reports, but also for support requests, feature requests, etc. In fact, if a person's question is related to a module, it is generally considered more effective to write the support request on the issue queue as opposed to these Drupal forums.
Finally, let me note that there is a Drupal.org working group that is hard at work planning the next generation of D.O., and while I don't know for sure if thread subscriptions is high on their list, my guess is that it is. The planning is happening, in part at:
Thank you I always wanted to know how to do that, but I was directly referring to a forum on my own website. Is there any contributed module that can do subscription.
"I would rule the world - If only I had the source code"
R.A.Smith -- "ƒrÅzRâ§"http://www.exterbox.com
Try these. If you want unregistered users to be able to join the fun, you'll definitely want the first choice: comment_notify. It's also a simpler and more focussed module, while the "subscriptions" module allows registered users to subscribe to any site content. In a way it's more powerful for registered users, but it's also kind of confusing.
Now I know why I kept seeing this all over the place. Thought it was weird compared to (nearly) EVERY other forum I've even been on in which subscribing to your posts is NORMAL, and I never saw people telling you they were subscribing in a single post.
Chalk it up to another one of those purely Drupalese oddities.
*insert trollface here*
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