Re: [Exim] query about verifying aliases

> On Wed, 18 Oct 2000, Phil Chambers wrote:
>
> > I would very much like to have exim interrogate remote systems when they are in my
> > local domains list. Given that they are on my network and will give a rapid
> > response it would not be too expensive. I can also be sure that they do verify at
> > RCPT time.
>
> By "local domains" I presume you mean some list of on-site domains, as
> opposed to Exim's local_domains setting.

I do, in fact mean those in local_domains as things stand. Though I can see that
you might also be confident that other domains would give a quick response.

>
> The basic code to do this isn't too hard, and it could of course be
> controlled by a list of domains. There is even some embryonic,
> experimental, commented-out code.
>
> I see the point for on-site domains. It turns out to be less useful in
> general, because some big domains (e.g. aol.com, unless they have
> changed recently) accept all addresses and bounce them later.

Presumably aol.com have a significant volume of non-returnable bounce messages to
deal with. I have always taken the view that one should refuse at the SMTP stage if
at all possible. Even on my second-level MX machine I refuse messages which the
primary system would refuse. This makes the configuration of the secondary machine
almost as complicated as the primary and all alias information must by syncronised,
but it presents a consistent view to the outside world.

Phil.
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Phil Chambers (postmaster@???)
University of Exeter