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

[Timo Sirainen]

On 8.4.2013, at 1.51, Rich Wales <richw at richw.org> wrote:

> When I use the mdbox format, there are a bunch of LIST and LSUB commands
> whose responses mention INBOX.Trash with the \Noselect and \HasChildren
> flags (the Trash folder for this particular account happens to contain
> subfolders).  Before trying to save a message in the Trash folder, the
> client did a "SUBSCRIBE INBOX.Trash" (which succeeded) followed by a
> "STATUS INBOX.Trash" (which failed with "NO Mailbox doesn't exist").
> 
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> 
> When I use the Maildir format, the raw log never mentions the \Noselect
> flag in connection with the INBOX.Trash folder.

Yeah, this is the difference between Dovecot's LAYOUT=fs and LAYOUT=maildir++ backends, which is also exposed to IMAP clients. With maildir++ there are no \Noselect folders possible. Whether that's a good or a bad thing I'm not entirely sure. I've been wondering earlier also if I should change the behavior somewhat, or make it configurable.

> So, with the mdbox format, Larch did not CREATE the folder before trying
> to SELECT it.  And Dovecot was flagging INBOX.Trash with a \Noselect flag
> (which was not the case with the Maildir format).

I'd say this is a Larch bug. It's relying on some specific way that some IMAP servers work.