[Users] how to effectively delete messages from Google IMAP (problem and solution)

[Pierre A.]

Dear Claws Mail users,

in Google IMAP accounts, I have noticed that Empty
wastebin... does not actually delete messages therein, as they stay in
[Gmail]/All Mail folder.

As a particularly annoying consequence, spam ends up untagged and mixed
with all other messages in All Mail, which would make All Mail a
complete mess in the long term.

I have found a similar complaint there :
https://support.google.com/mail/thread/4933937?hl=en

One way to actually delete messages is to put them in folder
[Gmail]/Trash, then go to the Gmail web client, open Trash, use Delete
forever, or, so they write, wait 30 days until trashed messages die out.

SOLUTION in Claws Mail

Edit account > Advanced > Put deletes messages in ... [Gmail]/Trash.

If I am correct, I will add this to the Claws Mail FAQ / Gmail article.