title: Outlook emails sent to invalid email with URL in them get clicked
body: <p>We are deploying an app where after signing-up you receive an email to a URL with a token that will call an API that simply switches a bool in the DB called confirmed. There is no other way to alter this bool other than through this API.</p>
  <p>We recently switched our gmail smtp to an outlook365 one and discovered that any email that is invalid gets this boolean toggled. To be more specific I've noticed that there are two types of invalid emails:
  One where we receive an email from Microsoft Outlook</p>
  <p><code>Your message to test@whatever.com couldn't be delivered.</code>
  <code>test wasn't found at whatever.com.</code></p>
  <p>and another where we receive the same email from <code>postmaster@officedepot.onmicrosoft.com</code></p>
  <p>Only the ones received from postmaster are getting validated.</p>
  <p>I believe the links are somehow automatically being called?</p>
  <p>Could anyone validate my theory?</p>