title: dark mode not working for received html emails thunderbird 91.7 / Windows 10
body: <p>I can enable dark mode in thunderbird (<code>tools/preferences/Add-ons and Themes</code>).
  However received emails still have white background and black text color.</p>
  <p>It seems that this comes from the fact that the emails are written in html (mostly company emails) and not plain text.</p>
  <p>If I go to <code>View / Message Body As / Plain Text</code> the text now shows in the dark colors I specified under <code>tools / preferences / general / Language &amp; Appearance / colors</code> where I configured some dark-mode-like colors.</p>
  <p>However now all my emails have bad formatting.</p>
  <p>Can I achieve the same result without switching to plain text view?</p>
  <p>My specs:<br />
  Thunderbird 91.7 64bit<br />
  Windows 10</p>