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When I compose and send an email (I always write plain-text emails) in Thunderbird, it always truncates my sentences and adds line breaks in the middle of my sentences.

How do I turn this feature off? It is quite annoying to me.

For instance, when I send people long URLs, the URL gets cut in the middle because of the automatic line breaks.

I am using the latest Thunderbird 9 for Mac OS X

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up vote 24 down vote accepted

Disable word wrapping in outgoing messages

  • Edit -> Preferences -> Advanced -> General -> Config Editor
  • Set the preference called "mail.wrap_long_lines" to false

See also:

... mail.wrap_long_lines to control the wrapping of long lines (defaults to true)

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This did not work for me until I toggled mailnews.wrap_length to zero as well. Then it worked like a charm, even with wrap_long_lines to false. This answer did point me towards the Config Editor, which is a good thing. – Joost Aug 12 '13 at 13:36
Moreover, I had to close and re-launch TB to make it notice the new setting. For the record, this happened with TB 24 under Ubuntu 12.04 x64. – Marcello Romani Mar 11 '14 at 12:44
It's enough to close the mail window (save as draft, close and reopen if you do not want to start over). – fuenfundachtzig Jul 23 '14 at 9:42
@Joost, setting the "mailnews.wrap_length" to 0, actually did fix it for me. Thanks. – Vicer Mar 3 '15 at 22:17

There is also an addon that can be used to disable the wrapping without messing with the configuration editor:

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Concerning URLs, it is actually sufficient to enclose them in < and >.

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@chipperyman573 Question title: "Tell Thunderbird not to [...] wrap lines" question body "for instance [...] long URLs". One answer: put it between < and >. Not as good as the accepted one, yet a lot quicker and also working if you prefer to have the remaining text wrapped – Tobias Kienzler Feb 16 '14 at 8:04
Yeah I misread the answer, sorry. – Frankie Feb 16 '14 at 8:08
@chipperyman573 no worries, I guess you saw it in the low quality queue, right? I'm also sometimes too quick there, that's why multiple votes are required after all :7 – Tobias Kienzler Feb 16 '14 at 8:14
Yeah, I flagged it and realized "I'm way to tired to be doing this" and took a nap. Didn't last long though sadly... – Frankie Feb 16 '14 at 8:15

Settings mailnews.wrap_length to zero disables wrapping on compose window, but as a side-effect does not wrap sent messages.

I addressed this problem by setting:

mailnews.wrap_length 0
mail.compose.wrap_to_window_width true
plain_text.wrap_long_lines true
view_source.wrap_long_lines true
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Can you give an example of how it doesn't "wrap sent messages"? I'm wondering if I should use your settings or the basic mailnews.wrap_length version. – Paul Oct 25 '15 at 16:25

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