[Dovecot] Strange behaviour when add new mailbox to IMAP (v 1.2.13)

[Alexander Chekalin]

Hi,

I think I need to ask you for advice. Personally I face that for the 
first time and hardly imagine this could be possible at all, but...

My setup is simple: I have one mail server where all of my mail accounts 
are stored, and another one to store backup of all mailings.

The scheme is simple, SMTP on first server forwards a copy of each 
message to address catchall at secondserver.my-domain. So whenever I need 
to restore any message I'll simple search for it on second server.

Both servers are have Dovecot 1.2.13 as IMAP servers. First server's 
Dovecot is sql-backed one, the second server's (in fact it serving just 
one box) is using passwd-style text file auth. Other than this, setup is 
pretty similiar, and everything is well, but here is the mystery:

I use Thunderbird (yesterday it was 3.1.1 and now it is 3.1.2) as my 
IMAP client. When I connect to my IMAP account on second server, and 
create mailbox, I see that there appears greyed folder named 
#virtual^Sent , and my new mailbox is in it.

When I do the same thing on first server, everything works just as I 
expect it (new mailbox created right under root of my IMAP account). If 
I create on second server new mailbox right under any existing (say, 
under Inbox) everything is fine also.


To check the problem I simplified my Dovecot config to the bare minimum, 
and it also won't work (#virtual^Sent still there). When I see on server 
disk, I see there .#virtual^Sent.NewTestMailbox dir (NewTestMailbox is 
the test mailbox I created), but there is no .#virtual^Sent dir.

I rebuilt Dovecot, and also tried to build 1.2.12, none worked.

May there be any solution for that?
Yours,
   Alexander Chekalin