Moving folders across backends

[Simon Beale]

I'm currently having an issue where clients (Outlook/Thunderbird etc)
can't delete shared folders if the folder resides on a different backend
to their INBOX.

Looking at the IMAP traffic, the client is doing:

. RENAME user.test.subfolder INBOX.Trash.subfolder
. NO Permission denied

If "subfolder" is on the same backend as INBOX, then instead it returns an
OK.

Is it possible to make these cross-backend RENAMEs work? And if so, what
do I need to look at?

(This is on centos 5.4, x86_64, running cyrus 2.3.16 from Simon Matter's
rpm 2.3.16-3)

Thanks for any suggestions.

Simon