Would you please provide more information? I'm not sure what you mean by plain text, since since writing in plain text has always been available.

Whenever I answer an message or compose a new one, I end up in an WYSIWYG editor with all kinds of formatting – see attached file for an example.

Here, there is graphical "stuff" such as vertical lines instead of `>` for indents, the line/paragraph breaks are unclear as they have different heights, e.g., making it unclear if there is an empty line or a "paragraph break", etc.

I also don't need the tabbar with all kinds of font setting and such.

I'd like a simple editor/compose window with, in first instance, exactly the "ASCII"-style text that I am going to send.

If, on top, different indentation levels are colored for easier recognition, that would be great.

- highlight account in left side of main pane - rightclick and select 'settings' - click 'composition&addressing - UNtick the box to compose in HTML

- as an aside, you control viewing of HTML messages in view>message body as>

I have TB set to view incoming HTML, but my replies are set as plain text, which appears to be what you want also.

Thanks @david!

Guess I was always searching for "plain text" or "text", will remember to (also) search for "html" in settings for related points.

Yes, currently I also have html display enabled for incoming messages, but want to always send pure text myself.