Continuing http://bugs.debian.org/1131305, an e-mail shows up in the DraftBox in the Web interface of Rambler but not in Thunderbird (TB). I presume that the e-mail is expunged. However, when I compact the folder or open and close TB (expunge on exit is set), nothing happens with this e-mail: it is still gone in TB and still visible in the Web interface.
Besides manually removing the old e-mail using the Web interface, the only thing that seems to clean up is starting to write another e-mail in TB. In particular, when I started to write this bug report in TB, the DraftBox in the Web interface got updated: the old draft finally disappeared, and the new draft appeared.
Here are my settings:
mail.imap.check_deleted_before_expunge=false
mail.imap.expunge_after_delete=false
mail.imap.expunge_option=2
mail.imap.expunge_threshold_number=20
However, I thought that compacting the folder in TB always triggers permanent deletion …