title: HTML Email <img> not working
body: <p>I've taken over a project that is using htmlmimemail to send html emails.</p>
  
  <p>Below is the source of the email:</p>
  
  <pre><code>&lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"&gt;
  &lt;p&gt;&lt;img src="https://VALID.IMAGE.LINK" alt=""&gt;&lt;/p&gt;
  &lt;p&gt;&amp;nbsp;&lt;/p&gt;
  &lt;p&gt;Dear test,&lt;/p&gt;
  &lt;p&gt;This is the body&lt;/p&gt;
  </code></pre>
  
  <p>The above image is not displaying however, when viewed in outlook/browser/webmail.</p>
  
  <p>Is there something I'm missing? This looks like a valid html email.</p>
  
  <p>The image src has been tested in a browser and it works.</p>
  
  <p>EDIT---</p>
  
  <p>When clicking on download images in my email client, the image still does not work, looks like below.</p>
  
  <p><img src="https://i.stack.imgur.com/vpZmo.png" alt="enter image description here"></p>