[exim] Rule Question

I have a small rules question, I'm running Exim 4.67 and SA 3.2.2. What
I want to do is automatically just drop/trash any piece of mail that has
the spam score set to a certain level. I don't check for spam in the ACL
rules I do it with a router and transport setting. I'm just curious if
there was a way to drop the message under my current setup or do I need
to change things around a bit? I'm thinking I should have to modify the
transport setup but I'm not sure. Any thoughts would be appreciated.

Router:# SpamAssassin
spamcheck_router:
driver = accept
no_verify
check_local_user = false
# When to scan a message :
# - it isn't already flagged as spam
# - it isn't already scanned
condition = "${if and { {!def:h_X-Spam-Flag:} {!eq
{$received_protocol}{spam-scanned}}} {1}{0}}"
require_files = /mail/${domain}/spamassassin/${local_part}/spamcheck
transport = spamcheck

Transport:
spamcheck:
    driver = pipe
    command = /usr/local/exim/bin/exim -oMr spam-scanned -bS
    use_bsmtp = true
    transport_filter = /usr/bin/spamc -u 
${lookup{$domain}lsearch*{/etc/exim/sa-list}{$value}}
    home_directory = /tmp
    current_directory = /tmp
    # must use a privileged user to set $received_protocol on the way 
back in!
    user = exim
    group = exim
    log_output = true
    return_fail_output = true
    return_path_add = false
    message_prefix =
    message_suffix =