Works perfectly Rated 5 out of 5 stars

Many thanks! I was deeply dismayed to find that the update from Thunderbird 3.1.6 to 3.1.7 not only broke keyconfig[1] and Rewrap Toolbar Button[2], but Nightly Tester Tools stopped showing its force addon compatibility button. I upgraded Nightly Tester Tools from 2.something to 3.0, no change, utterly refused to let me unlock the addons that, after all, were still working perfectly while incompatible.

So I ditched it and installed this in its place, and it's working. That will keep me wrapping and avoiding accidental quits for the foreseeable future.

[1] keyconfig is (almost) ESSENTIAL for anyone who also uses Outlook, as Outlook's mark as unread is ^Q, whereas Thunderbird uses that for Quit!! Incredibly annoying. (I qualify that with "almost" because, after all, I can also resolve this trivially with AutoHotkey like where I've make ^D exit console windows, ^W close JujuEdit etc. Outlook has some truly lousy shortcuts.)

[2] This is useful since Thunderbird's message editor stinks, both for HTML and for plain text. I still miss Mac Outlook Express, all these years on. Dynamic quote colouring, intelligent auto rewrap etc. Sadly one of my add-ons has broken even the blue colouration for quoted text in plain-text e-mail ... never figured out quite what went wrong there, but that "feature" was hopelessly broken even when it did "work" (kept getting the colour wrong)

This review is for a previous version of the add-on (0.7.1-signed).