[Dovecot] with mbox format doveadm ignores subfolders of inbox

[Jürgen Obermann]

Hello.

After we switched the format from mbox to mdbox on our dovecot  
(version 2.1.9) servers last week, some of our users were missing the  
subfolders of their inboxes. So far we thought that with the mbox  
format it is not possible to have mail folders containing both  
messages and subfolders. Now we know that there is one exception from  
this rule: the inbox. With mbox format dovecot supports subfolders of  
the inbox, and a few of our users actually detected and used this  
feature! Internally the messages are stored in /var/mail/user or in a  
file named 'inbox' and the subfolders are in the directory 'INBOX'.  
(The OS is case sensitiv.)

The problem was that doveadm and dsync do not support subfolders of  
the inbox and therefore these folders did not get synchronized from  
our old mbox server to the new mdbox dovecot server. The command

doveadm -o mail_location=mbox:~user123/Mail mailbox list -u user123 '*'

did not show any subfolder of INBOX, whereas the the following with a  
wrong mail_location showed that there are subfolders of INBOX

doveadm -o mail_location=mbox:~user123 mailbox list -u user123 '*'

Finally we could import the missing subfolders one after one in the  
mdbox server with commands like this:

doveadm import -u user123 mbox:~user123/Mail "" mailbox INBOX/subfolder all

It would be nice if doveadm could be changed to not overlook  
subfolders of the inbox with mbox format.

Greetings,
Jürgen
-- 
Hochschulrechenzentrum der | Mail: Juergen.Obermann at hrz.uni-giessen.de
Justus-Liebig-Universitaet | WWW:  http://www.uni-giessen.de/obermann/
Heinrich-Buff-Ring 44      | Tel:  0641-99-13054 (0641-99-13001)
D-35392 Giessen, Germany   | Fax:  0641-99-13009