RE: [Exim] Inbound Hosts without valid rDNS

On Tue, 30 Dec 2003, Eli wrote:

> 1) this topic has gone way off base from what this mailing list is for.

Probably, but it doesn't look as if you're going to let that stop
you...

> 2) nobody has control over someone elses DNS or reverse DNS either, so kick
> and scream all you want but it won't get you anywhere in making anything
> work the way you want it to.

Conversely, if they won't set their DNS up properly, they can kick and
scream as much as they like, but if an intended recipient refuses, for
that reason, to accept their mail, they haven't a leg to stand on.

> Also, the 2 main differing opinions/arguments are coming from people with
> different perspectives on it. I come from the large company perspective
> (and I think Wakko may come from there as well), and Greg and Tony seem to
> come from the end user perspective where they expect to get full control
> over everything.

Something wrong with your analogy. If it's a company, they should
expect to do it right - or more likely to have their provider do it
right for them. Else they'd be advised to change providers.

End users (whatever they might exactly be in your concept) have a much
shorter lever to make anything happen the way that it should. But any
non-trivial provider _should_ be providing a proper outbound mail
relay host, from which any self-respecting peer MTA would be willing
to accept mail. In that way, it doesn't matter that the end-user's
own IP address is dynamic, its DNS incompatible, etc. - all that
matters is that their provider is careful enough to avoid their mail
relay spamming its way into blacklists.

> I have a system, it will be called "server.domain.com". It hosts my
> website, and it also hosts my email. It has IP 10.0.0.1. You'd all say
> that reverse DNS for 10.0.0.1 should return "server.domain.com" - which so
> far would be correct. Now say I make a pointer for that system called
> "mail.domain.com" since it also hosts mail, and I want it to have a
> different name when dealing with email. Now what happens with reverse DNS?

Maybe you should be reading past discussions on this list. Whether or
not you consider the list to be an appropriate forum for it, the topic
*has* been discussed before, you know. (Clues: multiple PTR records,
CNAMEs etc.).