title: Flex / Grid properties are deleted in gmail email
body: <p>I have a script in PHP that sends the following HTML by mail :</p>
  
  <pre><code>&lt;html class="no-js" lang="en"&gt;
     &lt;body&gt;
        &lt;div style="width: 70%;background-color: #060b2b;margin: auto;flex-direction: column;display: flex;"&gt;
  
          &lt;h1 style="margin-top: 50px;color: white;margin-left: auto;margin-right: auto;"&gt;Vous avez reçu une nouvelle notification.&lt;/h1&gt;
  
          &lt;div style="width: 80%;padding: 50px;margin-top: 50px;background-color: #222;margin-left: auto;margin-right: auto;display: flex;"&gt;
              &lt;p style="color:white;margin: auto;text-align: center;"&gt;{{$notification}}&lt;/p&gt;
          &lt;/div&gt;
  
          &lt;a href="" style="margin-top: 50px;margin-bottom: 50px;margin-left: auto;margin-right: auto;color: white;padding:15px;background-color: #0E0E0E;"&gt;Accéder à mon compte&lt;/a&gt;
        &lt;/div&gt;
     &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>But the email received (when I inspect the main div) doesn't show the property <code>flex-direction: column;</code></p>
  
  <p>It seems that gmail filters those properties ?</p>
  
  <p>Is this normal ?</p>