Author: John Burnham Date: To: 'exim-users@exim.org' Subject: Re: [exim] Different target hosts and types for a Exim gateway
> Now the bit that has me stumped is how do I handle the situation for
> recipients where I need to lookup the MX for their domain and for
> literal IP addresses instead of hosts?
>
>
> Looking at the literal IP issue first, I can't find any options on how
> to route those. The 'route_data' option only appears to allow a host
> list, not literal IP's. I could use any help on this as my reading of
> docs and googling is not helping much here.
Do you mean you're specifying an IP address for the host you wish to connect to ? That's perfectly valid:
"Hosts may be listed by name or by IP address. An unadorned name in the list of hosts is interpreted as a host name. A name that is followed by /MX is interpreted as an indirection to a sublist of hosts obtained by looking up MX records in the DNS. For example:
route_list = * x.y.z:p.q.r/MX:e.f.g
If this feature is used with a port specifier, the port must come last. For example:
route_list = * dom1.tld/mx::1225"
so route_list = example.domain 1.2.3.4 is perfectly valid.
If, instead you're talking about ip literals (ie foo@???) then have a look at the ipliteral router and note that you need to set allow_domain_literals = true in the main config section for them to work.
>
> As far as MX lookups are concerned, a couple of possible
> options appear
> in the docs, but I'm not sure if they are graceful, wasteful or plain
> illegal.
>
Well, to make it do an MX lookup you have something like
route_list = domain domain/mx
(see example above) so I'd look to alter what your select returns to append /mx to the end. Does that make sense ?