Rated 5 out of 5 stars

As the developer Jan mentioned in a comment, replacement for Thunderbird 78.4.0 (64bit) exists and works. Available here: https://addons.thunderbird.net/de/thunderbird/addon/toggle-line-wrap/

Rated 5 out of 5 stars

Very good plugin, one of the most essential I use. Unfortunately
It doesn't work with TB 78.2.2. New version is highly anticipated.
Thank you!

As my distro force-migrated me to 78.4, I had to address that issue, finally:
Please have a look at https://addons.thunderbird.net/de/thunderbird/addon/toggle-line-wrap for a successor.

Rated 3 out of 5 stars

Great that it should work again on TB68, but the hotkey change seems to make it unusable on OSX (no native "Alt" key; TB binds that to Option, but Option-W is already a system shortcut for alternate text entry [capital-Sigma])

Yeah, selfish decision of mine, see http://git.kiszka.org/?p=togglewordwrap.git;a=commit;h=06e80bf1e7a912328ba71e1bd62611b30dca05fe.

Good news: With TB 78.4 and https://addons.thunderbird.net/de/thunderbird/addon/toggle-line-wrap you can modify the shortcuts again (Add-ons Manager - click on gear - Manage Extension Shortcuts).

Rated 5 out of 5 stars

Loved the previous versions. What's the hotkey on a Mac for this new version?

Rated 5 out of 5 stars

Great add-on.

May I know whether it's possible to disable word wrap by default as I use External Editor most of the time? I tried setting mailnews.wraplength=0 but then the add-on can no longer enable word wrap. Tweaking mail.wrap_long_lines and plain_text.wrap_long_lines didn't help, either.

To my understanding (I've only inherited the code), the add-on needs a non-zero setting when opening the editor in order to apply a concrete value for enabling the wrapping. Could be changed but would require to configure in the add-on what the wrap length should be. For that, we lack infrastructure so far. Same goes for pre-setting the add-on to "disabled" state. Contributions would be welcome, I'm currently lacking time for this.

UPDATE: This feature, control over the wrapping default when opening the editor, is now supported with the successor of this addon (https://addons.thunderbird.net/de/thunderbird/addon/toggle-line-wrap)

Rated 5 out of 5 stars

Works great, just like the old version, except that the hotkey seems to have changed (it's Alt-W now afaics).