Thunderbird has, or had, a plain text mode and a &quot;Simple HTML&quot; mode (other than only recognizing a subset of HTML, I don&#x27;t know what it does) for displaying messages. You can leave it in plain text mode and, in the event you really need to view HTML, switch it to &quot;Simple&quot; or full HTML. It also can block remote images and, I think, all JavaScript.<p>The wonderful Nostalgy add-on provides a very responsive keyboard interface.<p><a href="https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;thunderbird&#x2F;addon&#x2F;nostalgy&#x2F;" rel="nofollow">https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;thunderbird&#x2F;addon&#x2F;nostalgy&#x2F;</a><p>I don&#x27;t know if current Thunderbird versions include all that, however.