[Dovecot] create Sub-Subfolders

[Phill Edwards]

> when a user tries to create a sub-subfolder in Archiv, he gets the message:
>
> "Mailbox doesn't allow inferior mailboxes"
>
> is there a spezial configuration in /etc/dovecot.conf needed?
>

>From memory I believe it depends on the format of the mailboxes. If
you're using Maildir format then you can create sub-folders, but if
you're using mbox you can't. It's possible to convert mailboxes from
mbox to Maildir, but if you have a lot of users with a lot of mail
then this could be a big task. Also, remember that if you do change
format you also need to modify Postfix (assuming you're using Postfix)
to deliver to that format.