[ On Tuesday, July 1, 2003 at 07:09:26 (+0530), Suresh Ramasubramanian wrote: ]
> Subject: Re: Now well off-topic - was Re: [Exim] how to configure HELO/EHLO and DNS for multi-homed hosts
>
> Greg A. Woods wrote:
>
> > Actually it almost never does. Virtually hosted e-mail domains
> > generally use very well configured mail servers. They do this by
> > pointing their MX records at these shared servers, and usually the mail
> > sent out by users of those domains is relayed via their access
> > provider's authorised SMTP relay. Remember there's not necessarily any
>
> Not always... look at a cluster of webservers - their MX is elsewhere,
> but they do run qmail-send or something similar, in order to send
> outgoing mail (cronjobs, mail from web interfaces ...).
Remember there need not be any correspondence whatsoever between the
name used by an smtp-CLIENT in its greeting command and the domain names
used in the "MAIL FROM:" commands it issues. You are making incorrect
assumptions that do not apply.
> Smarthosting all of them through a central server is not always feasible
Nor is it _ever_ even remotely necessary.
> Why should you care if forward DNS doesn't match rDNS by the way?
Because that's one of the primary reasons for having Reverse DNS in the
first place.
> Configuring rDNS isn't the problem at all. Getting your IP provider to
> delegate the in-addr.arpa zone to you?
Perhaps you misunderstand the reasons why the Reverse DNS is supposed to
be useful as a means of authenticating host domain names and the
addresses they point to.
> Well, that's often a real
> problem - even if you give them the appropriate bind config snippets to
> do this.
It is not necessary, or even desirable, for the Reverse DNS zones to be
delegated to the same authorities responsible for the forward DNS. The
whole point is to have a separate authority responsible for the reverse
DNS.
--
Greg A. Woods
+1 416 218-0098; <g.a.woods@???>; <woods@???>
Planix, Inc. <woods@???>; VE3TCP; Secrets of the Weird <woods@???>
