[EXIM] Virtual domains and local delivery.

Greetings:

    I'm sure I'm years to late to this party.  However, I haven't come
across anything relating specifically to my problem in examining the
archives.

    Here's the situation:

    I have EXIM setup to handle multiple domains with mutliple alias files.
All appears to work nicely, except that an e-mail sent to a domain in which
the alias does not exist but an actual (UNIX) user does, gets delivered to
that user.  How can I bounce (return to sender) delivery of the mail when
everything fails BUT local delivery?

    I have consulted the EXIM FAQ and all the sample configurations, but
none seem to address this issue or even hint that it could be a problem.

    Here's part of my configuration file:

######################################################################
# TRANSPORTS CONFIGURATION #
######################################################################
# ORDER DOES NOT MATTER #
# Only one appropriate transport is called for each delivery. #
######################################################################

remote_smtp:
driver = smtp
headers_remove = "sender:x-mailer"

local_delivery:
driver = appendfile
file = /var/spool/mail/${local_part}
delivery_date_add
envelope_to_add
return_path_add
user = ${local_part}
group = mail
mode = 0660
headers_remove = "sender:x-mailer"

address_directory:
driver = appendfile
no_from_hack
prefix = ""
suffix = ""

address_pipe:
driver = pipe
return_output

address_file:
driver = appendfile
delivery_date_add
envelope_to_add
return_path_add
address_reply:
driver = autoreply


######################################################################
# DIRECTORS CONFIGURATION #
# Specifies how local addresses are handled #
######################################################################
# ORDER DOES MATTER #
# A local address is passed to each in turn until it is accepted. #
######################################################################

userforward:
driver = forwardfile
file =
/scsi2/home/${lookup{${local_part}}lsearch{VIRTUAL/${domain}}{$value}{$local
_part}}/.forward
user = root
no_verify
check_ancestor
filter

system_aliases:
driver = aliasfile
file = /exim/etc/aliases
search_type = lsearch
file_transport = address_file
pipe_transport = address_pipe

virtual_smartuser:
driver = smartuser
new_address =
${lookup{${local_part}}lsearch*{VIRTUAL/${domain}}{$value}fail}
qualify_preserve_domain

virtual_local:
driver = aliasfile
domains = CUSTDOM
file = VIRTUAL/${domain}
search_type = lsearch*
qualify_preserve_domain
transport = local_delivery

#localuser:
# driver = localuser
# transport = local_delivery
# no_more

    Anyone's assistance would be greatly appreciated.

--
Michael Raffeld