Maildrop "user unknown. Command output: Invalid user specified"

[tôba <toba@tsepa.net>]

Hello all,
With postfix and maildrop, I have this issue. Mails cannot be delivered
and in mail.log, I have this:

...relay=maildrop, delay=0.81, delays=0.8/0/0/0.01, dsn=5.1.1,
status=bounced (user unknown. Command output: Invalid user specified. )

I saw at google that this problem happenned already with others but I
could not find the solution.

My OS: Debian Etch

Try to make running: Postfix and Courier with maildrop delivery.

My relative (i think) postfix conf:
virtual_minimum_uid = 6060
virtual_gid_maps = static:6060
virtual_uid_maps = static:6060
virtual_alias_maps =
proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf,
hash:/etc/postfix/virtual virtual_mailbox_domains =
proxy:mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_mailbox_maps =
proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_transport = maildrop virtual_mailbox_base = /var/vmail/
maildrop_destination_concurrency_limit = 2
maildrop_destination_recipient_limit = 1

Maildrop suid:
tsaida:~# whereis maildrop
maildrop: /usr/bin/maildrop /usr/X11R6/bin/maildrop /usr/bin/X11/maildrop /usr/share/maildrop /usr/share/man/man1/maildrop.1.gz
tsaida:~# ls -l /usr/bin/maildrop
-rwxr-sr-x 1 root mail 162132 2006-10-08 18:11 /usr/bin/maildrop
tsaida:~# 

Postfix master.cf
maildrop  unix  -       n       n       -       -       pipe
  flags=uR user=vmail argv=/usr/bin/maildrop -d $recipient -w 90

Originally, (from a howto,) it was like the following but somewhere in a
mailinglist archive, the fellow suggested the above config.

maildrop  unix  -       n       n       -       -       pipe
flags=ODRhu user=vmail:daemon argv=/usr/bin/maildrop -w 90 -d
${user}@${nexthop}  ${extension} ${recipient} ${user} ${nexthop}

Can someone help me?

Best regards,

Tôba.