Is there any way to stop the subscription to ALL of the threads? I seem to be able to only unsubscribe to individual threads.
In your control panel you should be able to see your subscriptions, under “Utilities”. Also under “Email Settings” you can turn off the option to get notified whenever you post to a thread. (I’ve always had this turned off ...)
You can also double check when you post to a thread that the “Notify me via email when someone posts in this thread” checkbox below is NOT checked.