Re: [Exim] Domain literals: weighing up the arguments

Top Page
Delete this message
Reply to this message
Author: Tony Finch
Date:  
To: rmk+exim
CC: exim-users
Subject: Re: [Exim] Domain literals: weighing up the arguments
Russell King <rmk+exim@???> wrote:
>
>My problem with IP literals is that (eg) postmaster@[myrelaymtaip] doesn't
>exist in the first place. Note: I'm not saying that postmaster@mydomain
>does not exist; it most certainly does. However, because the externally
>reachable MTA purely provides filtering and routing with _zero_ local
>users, it doesn't have a postmaster address of its own. It doesn't
>even have any local domains as such. (It has a fixed set of domains
>which it does relay for, and that's all.)


Note that if Exim receives a message sent to <postmaster> (unqualified) it
will use qualify_domain to turn it into a full email address. This address
must work, and in fact it's hard to break it and still have working
cron email etc. Once you notice this, it's easy to add a simple router
to support postmaster-only machine-specific domains in the same way.

    postmaster:
        driver        = redirect
        domains        = @ : @[]
        local_parts    = postmaster
        data        = postmaster@${qualify_domain}


Note that multi-homed machines, or machines whose reverse DNS differs from
their primary hostname, should have all their aliases in the domain list.

Tony.
--
f.a.n.finch <dot@???> http://dotat.at/
RATTRAY HEAD TO BERWICK ON TWEED: SOUTH OR SOUTHWEST 3 OR 4, INCREASES 4 OR 5,
LOCALLY 6 NORTH FROM FIFE NESS LATER. EARLY MIST IN FORTH AND TAY, OTHERWISE
FAIR. GOOD, BUT POOR IN MIST. SLIGHT, BECOMES MODERATE IN NORTH.