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

[Eric Abrahamsen]

Gijs Hillenius <gijs@hillenius.net> writes:

> 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.

No, no flags are set. From IMAP's point of view, splitting is simply a
MOVE operation. Sorry, I misspoke earlier when I said the messages were
*copied* back into the same group. They're actually MOVEd. That means
there's only ever one copy of the message, but it gets a new UUID
number each time.

No new flags are set at all.

E