I cannot make Thunderbird break lines in my E-mail to specified length when they are composed in HTML, even after I did the following:
the "mailnews.wraplength" in Edit->Preferences->Advanced->Config Editor is set to 80, as well as the boolean "mail.wrap_long_lines" which is set to true. Also, I have set the "mail.compose.wrap_to_window_length" to false. Still, lines in the HTML composed E-mail are broken at window length, even after restarting Thunderbird.
I have installed the "Toggle Text Wrap" addon and it's working fine, but this means I need to compose E-mail in text mode. Is it possible to make Thunderbird split up endless, non-readible lines when using composing in HTML and with pre-scribed fixed width?
Edit: Is there a way to set the window size when I start composing e-mails, so that the line breaking that is somehow fixed to the window size, works on a smaller window?