When he clicks Quit, it would be nice to warn about prefs that got changed that that won't be saved, if any.
(he -> the user)
Created attachment 1712 [details] Flash
The content of attachment 1712 [details] has been deleted by Andrej Kacian <andrej@kacian.sk> who provided the following reason: Spam, unrelated to the bug. Possibly malware. The token used to delete this attachment was generated at 2017-01-21 11:13:03 CET.
Fixed in https://git.claws-mail.org/?p=clawsker.git;a=commit;h=b805274264e103348ae887f2b2f1b18b9dd846d1