I am using cyrus imapd on Fedora
The mailbox of a user is presenting a deep tree of nested INBOXes:
user.foo
user.foo.Apple Mail To Do
user.foo.Archives
user.foo.Archives.2011
user.foo.Deleted Messages
user.foo.Drafts
user.foo.INBOX.Deleted Messages
user.foo.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.Deleted Messages
user.foo.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.INBOX.Deleted Messages
[...]
If I delete the folder and reconstruct the mailbox the folders are re-created
/usr/lib/cyrus-imapd/reconstruct -r -f user.foo
all other users are OK
Any hint on why this structure is created?