[Thunderbird 91.6.1 (64-bit) on Windows 10] I have a question about the wrapping set-up and settings when composing a '''plain-text''' message and when viewing received messages. A lot of similar questions keep on popping up on the net. I think the reason is that there are many ambiguities in the [http://kb.mozillazine.org/Plain_text_e-mail_-_Thunderbird Thunderbird help pages], in the answers given in FAQ sites, and in the Thurderbird settings. Let me make clear the different ways in which "wrapping" applies and what I'm trying to achieve – without success – in my Thunderbird. When '''composing''' a '''plain-text''' message there should be three wrapping options: 1. While writing the message, some newlines (or linefeeds) are '''automatically added''' by Thunderbird '''in the message itself''', so that: (a) it '''appears wrapped''' while we write (even if we aren't typing any "enter" keys), and (b) '''the outgoing message itself contains newlines''' at the wrap points. The amount of characters at which Thunderbird should add the newlines is supposedly determined by some setting. 2. While writing the message, Thunderbird '''visually wraps''' the text so that it doesn't continue on a single line in the compose window. However, '''no newlines are added to the actual outgoing message''', so that each of its paragraphs is actually a single line. In this case, two things can happen for the recipient of the message: (a) if their client does a visual wrapping or reflow of the text, they will see the received text wrapped after some number of characters chosen by them; (b) if their client shows the received message as is, they will have to use horizontal scrolling to read long paragraphs, which are effectively single long lines. 3. While writing the message, Thunderbird '''does not do any visual wrapping of the text, nor does it automatically add newlines to it'''. So unless we type an "enter", the text keeps going on a single line and we'll have to use horizontal scrolling in the compose window, to see all of it while writing. On the recipient side, the result will be as in point 2. above. Now what I'd like to achieve is case 2. above: '''visual''' wrapping, but '''no automatic newlines in the actual outgoing message''' – so that any possible visual wrapping will be decided at the recipient's side. Which settings do I have to use to achieve this? I've tried several combinations of "plain_text.wrap_long_lines" and "mailnews.wraplength" without success. Some answers to similar questions on this site say that "setting mailnews.wraplength to 0 causes wrapping to the compose-window size"; the problem is that this wrapping is not just '''visual''': newlines are actually added to the outgoing message (case 1. above). Other answers say that ""setting mailnews.wraplength to -1 disables the wrapping"; the problem is that this seems to disable '''visual''' wrapping as well: in the compose window a horizontal scrollbar appear when writing a lot of text without "enter"s (case 3. above). Many answers of this kind are always ambiguous as to what they mean by "wrapping", whether a visual wrap or an actual adding of newlines while composing. I think that Thunderbird should have two distinct settings about this: 1a. "Do you want to automatically add newlines and consequently wrap the outgoing message?" Yes/No. if Yes, then 1b. "At how many characters should this automatic adding newlines happen?". If No, then 2a. "Do you want a 'visual' wrap of the message while composing, without newlines being automatically added to the outgoing message?" If Yes, then 2b. "At how many characters do you want such 'visual' wrapping to occur?". It is not clear to me whether or which settings in Thunderbird achieve this. When '''viewing a received message''', there should be the option whether we want a ''visual'' wrap of the message, and if so at how many characters; or whether we don't want it – so that we'll have to use a horizontal scrollbar to see long lines. Which Thunderbird settings, if any, achieve this? I hope I've managed to explain the problem; happy to re-edit my question to make it clearer. Thank you for your help!