Re: gnus INBOX housekeeping, kept (copies of) mail lying around

[Gijs Hillenius]

On  5 Jan 2016, Eric Abrahamsen wrote:


[...]

Earlier I reported:

>>>>>>>> Doing some Gnus imap folders housekeeping this morning, I found
>>>>>>>> that 8000 messages (called 131940.  131941. etcetera) /hiding/
>>>>>>>> in the imap's INBOX. It looks like these are all emails that
>>>>>>>> I've 'deleted' in Gnus, so they don't show. But for some reason
>>>>>>>> they're not actually deleted.

[...]

Which I was told could have something to do with 

>>>>>   (nnimap-inbox "INBOX")
>>>>>   (nnimap-split-methods nnmail-split-fancy)
>>>>>   (nnimap-unsplittable-articles
>>>>>    '(%Deleted))

[...]

>>>> This will be the problem. The normal value of that var is (%Deleted
>>>> %Seen). Removing %Seen means that all messages in your Inbox will
>>>> continue being split every time you check for new mail, even though
>>>> you've already seen them, and they're already in the Inbox.
>>>>
>>>> Essentially that means that all messages are copied from the Inbox
>>>> back into the Inbox each time you check mail.
>>>>
>>>> I pushed a change to nnimap.el some time ago that prevents the
>>>> splitting process from splitting mail into the group it's already
>>>> in, but you probably don't have that change in your version of
>>>> Gnus.

And now I wonder:

If my Gnus (5.13, part of Debian's Emacs) copies messages back into the
INBOX, does fancy-split set the delete/expunge IMAP flag to these?

Because, if it does not flag them for deletion, would that perhaps
explain why the nightly Cyrus pruning does not do anything? Cyrus is set
to remove from disk all messages that have been flagged for deletion for
3 days.