If there are about 50 possible actions to take on the page, and one of them is literally the last action, even after the 'save your settings' button, then that action is about as non-obvious as it can get while still being present in legible text. Flip it around - if you wanted an action to be obvious, would you put it there?

As a comparison, look at meetup.com, a similar endeavour in a lot of ways: their email notification screen[0] has a 'turn off' button before any of the individual checkboxes, which turns them all off (except password resets and the like).

[0] https://www.meetup.com/account/comm/