before queue contents filter

#smtp      inet  n       -       n       -       -       smtpd
smtp      inet  n       -       n       -       20       smtpd
  -o smtpd_proxy_filter=127.0.0.1:10025
  -o smtpd_client_connection_count_limit=10
#
# After-filter SMTP server. Receive mail from the content filter
# on localhost port 10026.
#
127.0.0.1:10026 inet n  -       n       -        -      smtpd
    -o smtpd_authorized_xforward_hosts=127.0.0.0/8
    -o smtpd_client_restrictions=
    -o smtpd_helo_restrictions=
    -o smtpd_sender_restrictions=
    -o smtpd_recipient_restrictions=permit_mynetworks,reject
    -o smtpd_data_restrictions=
    -o mynetworks=127.0.0.0/8
    -o receive_override_options=no_unknown_recipient_checks