allow adjustments / overrides to dovecot via extra.conf

[pipedreams-zz]

Summary

I would like to do adjustments to dovecot behavior in mailcow like display of the shared mailboxes and the use of per-user seen flags as well as virtual mailboxes.

I understand it is possible via extra.conf, which i used for additional settings for dovecot.

However, it is not possible to adjust the behavior of the shared namespace as the file shared_namespaces.conf is auto-generated by mailcow.

As i understand from dovecot documentation, different namespace definitions inside the conf are merged as long as they have the same name like "Shared". But this is not working here as i expect, dovecot starts but in SOGo interface there are no mailboxes shown at all.

I was wondering which is the hierarchy of the conf files when there is different or even contraditory settings in these. Should settings in extra.conf override the settings?

Motivation

To be able to have a clear way how to make custom settings to dovecot like display of the shared mailboxes (showing the email rather than the user name, no explicit inbox shown, using private seen flags).

Can extra.conf always just override settings with the same name in dovecot.conf?

Additional context

These are the settings i have in our existing mailserver in dovecot.conf and it yields me the desired behaviour.

mail_shared_explicit_inbox = no

namespace {
    type = shared
    separator = /
    prefix = Shared/%%u/
    # a) Per-user seen flags. Maildir indexes are shared. (INDEXPVT requires v2.2+)
    location = maildir:%%Lh/Maildir/:INDEXPVT=%Lh/Maildir/Shared/%%u
    # this namespace should handle its own subscriptions or not.
    subscriptions = yes
    list = children
}

How can Virtual Mailboxes be created in mailcow? Currently, it works for me like this:

namespace {
    prefix = Virtual/
    separator = /
    location = virtual:~/Maildir/virtual:INDEX=MEMORY
    list = yes
    subscriptions = yes
    hidden = no
}