SUMMARY Thunderbird has a very useful function to display the messages that have html, you can choose the version without modifications (just like kmail does) and a simple version. In it the email is not broken as " brute " as when the html is removed from a message. The links are still displayed, I believe the title tags too (h1, h2, ...), lists, quotes, etc. It seems that it is converted to markdown. This function can be activated in Menu -> Display -> Formatting the message as -> Plain HTML I think that's an interesting approach to improve e-mail viewing. Examples: A fully html enabled email (no external images, of course) https://i.imgur.com/KsdM9X3.png Even email with the simplified version of thunderbird https://i.imgur.com/9gEaAep.png Kmail in plain text https://i.imgur.com/X7TBneb.png The simplified version is much better than the others. My opinion.