dovecot - Aug 2021 - Preventing clients from trying to create folders under inbox

Our Dovecot installation is configured as such:

mail_location =
mbox:/var/vmail/%u:DIRNAME=.mboxdata:INBOX=/var/vmail/%u/INBOX:INDEX=/var/vmail/indexes/%u

This allows us to continue using mbox formatted files, storing those
mbox data files in a file called .mboxdata.  This allows our users to
create folders and subfolders.  The only exception to this is our
inboxes, which are more traditional mbox files.

However, we have some Outlook users that insist on trying to create
subfolders of their inbox.  This doesn't work, since the inbox is a
file.  But Outlook still does it and it causes sync issues, as there is
now a subfolder under the user's inbox, but that subfolder is ONLY
present in Outlook (it isn't present on the server).

Is there anything that we can configure so that Dovecot instructs
Outlook that it cannot attempt to create subfolders under the inbox, but
allow subfolders elsewhere?

Thanks!
Bryan

> On 13/08/2021 19:09 Bryan K. Walton <bwalton+1608560055 at
leepfrog.com> wrote:
> 
>  
> Our Dovecot installation is configured as such:
> 
> mail_location =
mbox:/var/vmail/%u:DIRNAME=.mboxdata:INBOX=/var/vmail/%u/INBOX:INDEX=/var/vmail/indexes/%u
> 
> This allows us to continue using mbox formatted files, storing those
> mbox data files in a file called .mboxdata.  This allows our users to
> create folders and subfolders.  The only exception to this is our
> inboxes, which are more traditional mbox files.
> 
> However, we have some Outlook users that insist on trying to create
> subfolders of their inbox.  This doesn't work, since the inbox is a
> file.  But Outlook still does it and it causes sync issues, as there is
> now a subfolder under the user's inbox, but that subfolder is ONLY
> present in Outlook (it isn't present on the server).
> 
> Is there anything that we can configure so that Dovecot instructs
> Outlook that it cannot attempt to create subfolders under the inbox, but
> allow subfolders elsewhere?
> 
> Thanks!
> Bryan
You could try acl plugin, it might let you prevent this.

Aki