How do we unsubscribe from a thread's email notifications??

The email notifications I'm getting have the following footer:

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You were sent this email because you opted to receive email notifications when someone responded to this topic.

To unsubscribe, go here and disable your email subscription for this thread.

The "here" link simply takes me to the thread, with no visible options for unsubscribing.  The only work-around I've found is to disable all notifications in my profile preferences, which is something I'd prefer not to do as I may miss updates on threads that I am still interested in.

For example, I'd very much like to remove my subscription from the "Poll - New Community" thread, with 716 replies received so far!

I am aware of and found this link for the "forum subscriptions", which operate on a per-forum basis.  These are all set to "No" already.  Where are the thread options?