title: Include external stylesheets internally for email templates
body: <p>I'm trying to craft some nice email templates for my site, but I'm having a conflict between my desire for well-crafted code and functionality.</p>
  
  <p>My problem is that all of my email templates are formatted like standard templates:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;link rel="stylesheet"...&gt;
      &lt;/head&gt;
      &lt;body&gt;
          Some stuff
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>which displays just fine as a webpage, but in trying to send this as a formatted email, it's essentially just sending the <code>Some stuff</code> section, which means none of the formatting really makes it across.</p>
  
  <p>My current emailing code looks like this:</p>
  
  <pre><code>message = Message(
      subject="Subject",
      html= render_template(
          'emails/confirmation_email.html',
          confirmation_code=confirmation.confirmation_code
      ),
      sender = ("sender", "sender@gmail.com")
  )
  </code></pre>
  
  <p>I'm using Jinja2 templates and the Flask-Mail extension.</p>
  
  <p>Basically, I really want to include these stylesheets in my email, but I really object to including everything in a style tag.</p>