How to use dovecot only as POP3 server / prevent it from creating .imap directories?

[Joseph Tam]

On Wed, 17 Jun 2020, Josef 'Jeff' Sipek wrote:

> On Tue, Jun 09, 2020 at 12:32:18 +0200, Binarus wrote:
> ...
>> ./mail/inbox
>> ./mail/.imap
>> ./mail/.imap/dovecot-uidvalidity
>> ./mail/.imap/dovecot.list.index.log
>> ./mail/.imap/dovecot-uidvalidity.5edce848
>> ./mail/.imap/INBOX
>> ./mail/.imap/INBOX/dovecot.index.log
>> ./mail/.imap/INBOX/dovecot.index
>> ./mail/.imap/INBOX/dovecot.index.log.2
>> ./mail/.imap/INBOX/dovecot.index.cache
>
> The .imap directory isn't really about IMAP.  It is sort of a generic
> directory that just happens to have "imap" in the name.  The index files you
> see are required for various features inside dovecot to work properly.  Many
> of them are related to performance rather than a specific protocol.

Spot on.

> If you don't want the index files to live inside the users' home
> directories, take a look at the INDEX and CONTROL keys in the mail_location
> docs:
>
> https://doc.dovecot.org/configuration_manual/mail_location/#format
>
> While that still creates the files, you can move them off to a location that
> the users do not see.

Or you can create in-memory indices, but that is a solution to the wrong
problem.

By specifically stating in mail_location that ~user holds mailboxes,
you are telling Dovecot an untruth.  It's better to tell Dovecot user
mailboxes (other than INBOX) don't exist, rather than to push all the
indices under the carpet.

Joseph Tam <jtam.home at gmail.com>