[Exim] specifying a port in route_list

hi,

is it possible to specify a port to which to connect to when sending
messages to a machine as in route_list ?

the idea/situation i'm having is, i'm connected to an isp who has
certain pipes to off the country, and is also connected to the big
exchange chaos to which all other hungarian isps are connected to (who
have their own "external" pipes, too). now, every once in a while the
abroad links go down (nothing serious, but can be annoying if you just
_need_ to get a mail delivered:). i also have a box with another isp
over which i don't have complete control (i have root access and the
like, it'd just be nice not to mess it's current conf up too much).

i thought about crafting some retry rules that if a message can't be
sent in a specified amount of time, and the reason of the failing is
(could be) related to abroad links being down, i'd just reroute those
messages to a box having separate (thus probably working at the same
time) abroad pipes. now, the other box is running sendmail, which is
given, but i could set up an exim listening on a different port - the
problem is how to tell my exim not to connect to port 25, but to
something else ? (i think i could handle the other configuration
problems with loop detection and all that's appropriate here, i
haven't yet in detail thought about the deep catches here).

the reason i'd more like an exim than simple smarthosting with
sendmail is that if my link comes back up and the other is down for
some reason (happens, too), i could route them back more easily than i
could with sendmail (i think - i've never known sendmail that deep,
whatever deep this kind of configuration counts with sendmail).

so, can i specify a port in route_list (a quick skim at the host-list
format doesn't revealed anything) ? and whether the answer is yes
or no, am i making any sense to anyone or is it just another of those
early morning brainflaws ? (or maybe an alternative suggestion to the
problem?)

TIA,

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