Summary might not make the most sense... let me try to explain. This mainly affects my GMail account that I access from claws-mail via IMAP. In the 'Advanced' page of the account settings, I've set in the Folders section the correct places to put Sent mail (etc.) based on where GMail puts them if I use GMail's web interface. However, claws still displays the Sent (etc.) folder in its usual place as a direct child of Inbox, and will even go so far as to recreate them on the server (easiest way to trigger: right click on the account and select 'Check for new folders'). For GMail, this results in ugly new Labels named things like "[imap]/Sent" which I then have to manually delete from GMail's interface, as claws doesn't let me delete them. So basically, claws should understand that I've overridden those folder locations in the account settings, and not create or keep the 'default' copies of those folders.
Still present in Claws-Mail 3.9.3 It works for the Inbox (in some other bug reports, it seems there is also a double inbox), but I got "Sent" (instead of "sent-mail" which is assigned to be used) "Queue" and "Drafts" (instead of a local folder) For the trash it also works, but thats interesting somehow: In the Mailbox view the shown name is "Papierkorb" (german name of it), in the setting it's the IMAP-Folder "trash".+ Thanks anyway for providing this great program and support for it for so long! I love using it since years (already when it was the sylpheed and sylpheed-claws :)