[Dovecot] maildir autodetect failing. what's wrong with this setup?

[Richard]

i'm setting up for virtual_users w/ maildir.

i have in my dovecot.conf:

 auth default {
  passdb passwd-file {
   args = /etc/dovecot/imapd.passwd
  }
  userdb static {
   args = static uid=300 gid=300 home=/var/dovecot/mail
mail=maildir:/var/dovecot/mail/%d/%n/Maildir nice=10
  }
 }
 default_mail_env =
maildir:/var/dovecot/mail/%d/%n/Maildir:INDEX=/var/dovecot/indexes/%d/%n


in /etc/dovecot/imapd.passwd, i have:

 omn at server.com:{PLAIN}pass:300:300::/var/dovecot/mail:::

i've created:

 /var/dovecot/mail/server.com/omn/Maildir/cur

but, on login @ telnet with:

 x login omn at server.com pass

i see:

 dovecot: Aug 20 08:07:33 Info: auth(default): client in: AUTH   1
 PLAIN   service=IMAP    secured lip=x.x.x.x rip=x.x.x.x  resp=<hidden>
 dovecot: Aug 20 08:07:33 Info: auth(default): client out: OK    1
 user=omn at server.com
 dovecot: Aug 20 08:07:33 Info: auth(default): master in: REQUEST
 1       28584   1
 dovecot: Aug 20 08:07:33 Info: auth(default): master out: USER  1
 omn at server.com     static  uid=300  gid=300   home=
mail=maildir:/server.com/omn/Maildir      nice=10
 dovecot: Aug 20 08:07:33 Info: imap-login: Login:
user=<omn at server.com>, method=PLAIN, rip=x.x.x.x, lip=x.x.x.x, secured
 dovecot: Aug 20 08:07:33 Error: statfs(/server.com/omn/Maildir) failed:
No such file or directory
 dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): Effective uid=300,
gid=300
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): Namespace:
type=private, prefix=Private/, sep=/, inbox=yes, hidden=no, subscriptions=no
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): maildir autodetect:
stat($default_mail_env/cur) failed: No such file or directory
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): mbox autodetect:
data=$default_mail_env
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): mbox autodetect:
INBOX file: stat($default_mail_env) failed: No such file or directory
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): mbox autodetect:
has .imap/: stat($default_mail_env/.imap) failed: No such file or directory
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): mbox autodetect:
has inbox: stat($default_mail_env/inbox) failed: No such file or directory
dovecot: Aug 20 08:07:33 Info: IMAP(omn at server.com): mbox autodetect:
has mbox: stat($default_mail_env/mbox) failed: No such file or directory
dovecot: Aug 20 08:07:33 Error: IMAP(omn at server.com): Ambiguous mail
location setting, don't know what to do with it: $default_mail_env (try
prefixing it with mbox: or maildir:)
dovecot: Aug 20 08:07:33 Error: IMAP(omn at server.com): Failed to create
storage for 'Private/' with data: $default_mail_env
dovecot: Aug 20 08:07:33 Error: child 28587 (imap) returned error 89


thanks.