[Dovecot] Shared mailbox not showing in list

[Tom Clark]

I've setup a shared folder on my server which isn't showing in the list
command for the user it's shared with.

Can someone help? I have done everything correctly I believe.

The user sharing their mailbox is support@, while I'm the user being shared
with, tom@

namespace {
  type = shared
  separator = .
  prefix = Shared.%%u.
  location = maildir:%%h/Maildir:INDEX=~/Maildir/Shared/%%u
  subscriptions = no
  list = children
}

mail_plugins = acl
protocol imap {
  mail_plugins = $mail_plugins imap_acl
}

plugin {
  acl = vfile
}

# Support for multiple domains
plugin {
  acl_shared_dict = file:/var/vpopmail/domains/%d/shared-mailboxes
}

This what is in the dict file says:

shared/shared-boxes/user/tom at mailbox.com/support at mailbox.com

When running a GETACL as support at mailbox.com I get:

3 getacl Support
* ACL "Support" "tom at mailbox.com" lr "support at mailbox.com" lrwstipekxacd
3 OK Getacl completed.

However when I do a LIST "" * as tom at mailbox.com It doesn't have any mention
of the Shared maildir.

* LIST (\HasChildren) "." "Sent"
* LIST (\HasNoChildren) "." "Sent.Drafts"
* LIST (\HasNoChildren) "." "Sent Messages"
* LIST (\HasNoChildren) "." "Trash"
* LIST (\HasChildren) "." "INBOX"