Migrating from UW: Mailbox does not exist

[Jorey Bump]

Kjetil Torgrim Homme wrote:
> On Mon, 2006-09-18 at 16:41 -0400, Jorey Bump wrote:
>> I have another server to migrate, and would like these subdirectories to 
>> be recreated properly during the process, as there are many more 
>> accounts to move. Has anyone else encountered this and found a solution? 
> 
> how do you think imapsync can tell which folders should be created or
> not?  wouldn't other users be annoyed about empty interim folders being
> created?

imapsync is creating mailboxes in the namespace as long as they contain 
messages:

  UW: /home/jorey/archive/reports/mail  (mail is an mbox file)
  Namespace: user.jorey.archive.reports.mail

Resulting in:

  Cyrus: /var/spool/imap/user/jorey/archive/reports/mail/

What's missing is that imapsync doesn't create archive & reports as 
mailboxes (which may be the correct default behaviour, based on 
UW-IMAP's response). I want to find out how to translate these 
directories to mailboxes either in imapsync (if it's an option I've 
missed), or after the transfer with Cyrus.

By switching to Cyrus, I'm adding the ability to store messages 
alongside subfolders. After the migration, they still appear as part of 
the mailbox heirarchy in the client, but behave very differently than 
new folders that are created with Cyrus (the old UW ones are greyed out 
in Thunderbird, for example, and cannot hold messages, only subfolders).

They are also completely absent from the heirarchy in webmail (using 
squirrelmail), and there seems to be no way to make them appear, other 
than recreating the entire heirarchy under a temporary name, moving the 
messages, deleting the old parent, then renaming the temp parent to the 
old name. My users will be confused when these parents fail to appear in 
webmail, even though the children do.

After the migration, the only thing distinguishes these old UW 
directories is that they contain no cyrus.cache, cyrus.header, and 
cyrus.index files. Is there a way to force the creation of these files 
if they are missing in a directory?

>> I couldn't identify an option in the imapsync documentation or any way 
>> to apply this recursively to Cyrus mailboxes after migration. Any tips 
>> are welcome.
> 
> if you intend to use the folder to store messages in it, store at least
> one message there.

I wish I could. Sadly, this is not possible with UW-IMAP. These are 
directories on the filesystem, and they can contain only mbox files 
and/or subdirectories. There is no way to store a single message, as is 
possible with Cyrus or Maildir. This is a limitation of the mbox format, 
which stores multiple messages in a single file.