[Dovecot] mdbox and folders containing both messages and sub-folders

[Timo Sirainen]

On 6.4.2013, at 23.51, Rich Wales <richw at richw.org> wrote:

> and am using the Larch program to do an IMAP-to-IMAP copy of one of my
> family member's mail from the old Cyrus server to the new Dovecot server.
> When I examine the "mailboxes" directory tree, I see some directories
> that (correctly) contain both the renamed ".indexes" directory and also
> directories for IMAP subfolders.  However, the Larch output is showing
> many errors of the form "mailbox cannot contain messages", and some of
> the messages could not be migrated because of this problem.

What is the error message exactly? I'm wondering if the error is coming from Dovecot or if Larch is somehow confused internally and giving bogus errors.

> Am I doing something wrong?  Or is the "folders containing both messages
> and sub-folders" feature simply broken for the "mdbox" format -- meaning
> presumably that I'll be forced either to use the Maildir format, or else
> abandon Dovecot entirely and install Cyrus on my new mail server instead?

It works fine in mdbox, you can't disable it even if you tried.