I have two Cyrus IMAP server strictly identical. One with a local spool
and another one with a private spool on a NFS server.
The Cyrus IMAP server are version 2.1.17-3 on Debian Sarge.
When I delete a mailbox (via cyradm for example), the mailbox directory
is not deleted on the server with the NFS spool; but the content of the
mailbox is deleted (including the cyrus.header, cache et index).
On the server with the local spool, the mailbox folder is correctly deleted.