mailx & maildir & You have new mail in /home/<account>/Maildir

[Stevan Kanban <ojingo@nerim.net>]

Hi,
I 've got a problem with mailx.
All my mail stucture is Maildir based. Any MTU points to the same inbox, sent-mail, trash, ...
Now i want to do the same with mailx but it doesn't work:

<account>$ mail
mail: /home/<account>/Maildir: Is a directory
When sending a mail, it's the same:
# mail <account>
Subject: foo
foo
Cc:
mail: /root/Maildir/sent-mail/: Is a directory

I've searched on google and read carefully the manpage of mail to build the following /etc/mail.rc configuration:
set ask askcc append dot save crt
ignore Received Message-Id Resent-Message-Id Status Mail-From Return-Path Via Delivered-To
set folder="Maildir/"
set MBOX="Maildir"
set record="~/Maildir/sent-mail/"

Has somebody any idea where's the problem? By the way, the mail is sent anyway (but not recorded) and postfix do its job by 
delivering to <account>.

I succed in obtaining the message "You have new mail in /home/<account>/Maildir" when typing <enter> whereas when connecting 
i've got:
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
No mail.

My configurations:

in /etc/profile:
export MAIL="/home/$USER/Maildir"
export MAILDIR="~/Maildir"

in /etc/login.defs
#QMAIL_DIR      Maildir/
MAIL_DIR        Maildir/
#MAIL_FILE      .mail

It should be the same mehanism for annoucement that mail arrived both in login and in <enter> typing action, isn't it?

Thanks.
 
-- 
Stevan Kanban