Re: Why Gnus is creating .nnmaildir directory in my maildir?

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Jean Louis <bugs@gnu.support> writes:

> * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-04-14 01:05]:
>> But I will note that plenty of GUI mail clients keep their own
>> cache/data in something like a sqlite database, alongside the actual
>> message store. nnmaildir is unusable for large maildirs because it
>> tries to build the entire cache the first time it is run, and that
>> happens in quadratic time. If you start a new nnmaildir installation
>> from nothing, and add messages at a "normal" rate, it's not that
>> bad.
>
> I have tried all mail clients that deal with Maildirs. Just Gnus does
> that kind of mess. None of clients in any GNU/Linux distribution is
> similar to it.
>
> The only cache that I know that some client may use is the IMAP header
> cache, for some 20000 emails in various folders it is now 55 MB.

The header cache is exactly what the .nnmaildir directory
contains, and that's what takes up the space. It does keep some other
information in there, but I don't think that eats up a lot of disk.