title: Elasticsearch X-Pack builtin cluster alerts email
body: <p>I'm running ES 6.4 with X-Pack installed.
  There are builtin alerts for cluster awareness:</p>
  
  <p><a href="https://i.stack.imgur.com/cVdP7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cVdP7.png" alt="enter image description here"></a></p>
  
  <p>I'm receiving email alerts for cluster severity, shards allocation etc which are coming in from "X-pack Admin" with one of my email addresses. These watchers are most probably the origin.
  Where are these Watchers taking the destination and From email addresses from?</p>