[exim] rejecting hosts pointing to local host - did I do it …

I finally got around to looking in to an issue I've been having with a few
domains that I *used* to host. The error was in my dnslookup router and was
being caused by domains that I host, but just not for email.

I was seeing email coming in for these domains since their A record pointed
to me (www and mail are the same system) but they weren't in my list of
domains I handle email for. This was causing my system to produce "remote
host address is the local host" errors and Exim was deferring the messages.

I did some quick reading and figured out I should probably have "self =
fail" added to the router, so that in all it is:

remote_address:
        driver                  = dnslookup
        domains                 = !+domain_virtual : !+domain_aliases
        ignore_target_hosts     = 0.0.0.0 : 127.0.0.0/8
        cannot_route_message    = Insufficient DNS information found for
$domain
        transport               = remote_delivery
        self                    = fail
        more                    = no

Now, I did some very quick tests and it seems to have solved the problem (it
now fails, instead of defers which is what I want), but I am just sending
this "out there" in case having "self = fail" may bring on other unexpected
results that I'm not anticipating?

If anyone sees anything wrong with this, please let me know.

(this router is supposed to be only for external domains as the domains line
somewhat shows, and all "local" domains should/must be defined in
domain_virtual or domain_aliases - so it should be ok to fail domains
pointing to localhost that aren't a recognized domain.)

Thanks,

Eli.