title: How is a /@ url found in spam able to be resolved?
body: <p>I recently received an email containing the following chunk (don't click!):</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;A HrEf="/@/0X0a290d92b/UALI=28389-UI=176738575-OI=279-ONI=5477-SI=0-CI=0-BI=577-II=27913-IDSP=1-KLEM=11-TIE=A-IDE=276135-MID=572-FID=0-DIOM=0" sTyLe=color:#000;font-size:10px;font-family:arial;&gt;
  &lt;span&gt;UNS&lt;/span&gt;&lt;/a&gt;
  </code></pre>
  
  <p>Here is a link to the raw email: <a href="https://gist.github.com/anonymous/16963a230cab0a3a1bcfc81209f297f1">https://gist.github.com/anonymous/16963a230cab0a3a1bcfc81209f297f1</a></p>
  
  <p>As far as I know, <code>/@</code> is not a valid url. How is my browser able to resolve it to a site?</p>