[exim] "send_to_smart_host" questions

Server set up:

Exim 4.5 (FreeBSD port) on dual-homed FreeBSD Stable 5.3 box receiving mail from
LAN only with no local deliveries.

Local messages (from LAN users to LAN users) relayed to smarthost on LAN (XMail
with Dovecot) on Linux box.

Other messages delivered directly by dnslookup.

Relevant configuration parameters:

domainlist local_domains =
#
begin routers

send_to_smart_host:
    driver              =       manualroute
    route_list          =       [local.domain] 192.168.1.69
    host_find_failed    =       freeze
    transport           =       XMail_smtp
#
begin transports

XMail_smtp:
  driver                =       smtp
  port                  =       50000
  command_timeout       =       30s

Questions:

Everything works as intended, local messages are relayed to the Xmail server for
delivery and other messages are delivered directly. Is this a fluke or is this
set up acceptable?

Is there a better way to do this? (Local deliveries by this server are not an
option.)

Thank you.

--
Walentyn