Unable to view shared mailbox

[dev]

Hi All,
I have a mailing list I'd like to archive and share with a
handful of users. The users are all in OpenLDAP.

10-auth-system.conf.ext is setup with "driver=pam" so it
appears anyone in LDAP who already is able to SSH into the
server may also connect to dovecot with same username/password
they use in LDAP.

I have a shared mailbox directory called LISTS_Archive. The
system directory is /home/shared_imap.  I can connect to
dovecot using LDAP credentials (using Thunderbird) and this
shared folder (LISTS_Archive) is grayed out. I assume I have
acls wrong?

What I want is for users in LDAP to access the LISTS_Archive
imap folder as a shared folder for everyone. Only R/O access
however (which is 'lr' in acl file I think).

Would someone please point out what I've missed?  Thank you.

#
# egrep -v '(^$|\#)' /etc/dovecot/conf.d/10-mail.conf
#
mail_location = maildir:~/.maildir

namespace inbox {
   type = private
   separator = /
   inbox = yes
}

mail_plugins = acl
plugin {
   acl = vfile:/etc/dovecot/acls
}

namespace {
    hidden      = no
    inbox       = no
    location    = 
maildir:/home/shared_imap/:INDEX=~/Maildir/shared/%%u:INDEXPVT=~/Maildir/shared/%%u
    prefix      = LISTS_Archive/
    separator   = /
    type        = public
    list        = yes
    subscriptions = no
}


#
# egrep -v '(^$|\#)' /etc/dovecot/conf.d/20-imap.conf
#
protocol imap {
   mail_plugins = $mail_plugins imap_acl
}


#
# dir /home/shared_imap/
#
total 8
drwxr-xr-x 7 root   root    4096 May 25 10:26 ..
-rw-rw-r-- 1 user384 mail-user    0 May 25 10:43 dovecot-acl-list
drwxrwsr-x 2 root   mail-user 4096 May 25 10:43 .

#
# cat /etc/dovecot/acls
#
* user=user384 lr