On 2007-05-15 at 23:24 +0200, Peter Thomassen wrote:
> I'm sorry, but I have found cases in which these routers don't work. Usually
> there is something specified like:
>
> example.org MX 10 mail.a4a.de
>
> Now I found that all subdomains of example.com are broken regarding e-mail;
An MX record for example.org says *nothing* about sub-domains.
Properly, you need MX records for them all; this has been true for a
long time, but there's backwards-compatibility for "the days before MX
records" in the SMTP routing spec, which says that an A record will be
looked for if there are no MX records.
I alluded to this with:
----------------------------8< cut here >8------------------------------
If your customers can end up with an A record for the domain pointing to
your system and no MX records then this won't be sufficient and you'll
need to add a lot more complexity.
----------------------------8< cut here >8------------------------------
when I was talking about the manual approach.
In my previous email, I pointed out that "self = pass" is necessary; in
the first mail, I mentioned it only to in connection with having to
set hosts_treat_as_local for a cluster for "self = pass" to work
properly.
> R: dnslookup_not_yet_hosted for info@???
> LOG: MAIN
> remote host address is the local host: sub.example.org (while routing <info@???>)
> info@??? cannot be resolved at this time:
> remote host address is the local host
"self = pass" fixes this, letting it continue on.
> Why isn't that passed on to the local routers? Do I have to set up MX
> records for *.example.org?
A DNS RR for "*.example.org" will only supply data for those labels
which don't already have RRs; if you have an A record for
sub.example.org then "*.example.org MX 10 foo.example.org." won't
generate an MX response for "sub".
Yes, anything which is a mail domain in a supported email address should
have MX records. If you're relying on A record fallback, you need "self
= pass".
See my mail:
Message-ID: <20070515182233.GA98683@???>
Regards,
-Phil
