On 09/09/13 14:36, Graeme Fowler wrote:
>
> graeme@boom ~]$ dig bcidahofoundation.org any
>
[...]
>
> ;; ANSWER SECTION:
> bcidahofoundation.org. 900 IN CNAME www.bcidahofoundation.com.
> bcidahofoundation.org. 85677 IN NS ns1.hover.com.
> bcidahofoundation.org. 85677 IN NS ns2.hover.com.
>
[...]
>
> ***Interesting bit here*** bcidahofoundation.org has no MX records,
> having only a CNAME at the zone apex which goes to... ta-da! The
> explicit hostname of www.bcidahofoundation.com.
>
> So nonesuch@??? gets internally rewritten in the
> envelope to deliver to nonesuch@www.bcidahofoundation.com.
>
Hi Graeme,
I've snipped much of your message to focus in on one particular part of
it in this reply, specifically the explanation you gave above.
1) Why should a CNAME cause the envelope to be rewritten at all?
2) This behaviour exactly contradicts the third paragraph in the Exim
documentation at
http://www.exim.org/exim-html-current/doc/html/spec_html/ch-address_rewriting.html
3) If I do a "mx" query rather than an "any" query, dig shows another
interesting detail:
;; ANSWER SECTION:
bcidahofoundation.org. 892 IN CNAME www.bcidahofoundation.com.
www.bcidahofoundation.com. 79792 IN CNAME bcidahofoundation.com.
bcidahofoundation.com. 600 IN MX 10 mail2.bcidaho.com.
bcidahofoundation.com. 600 IN MX 10 mail1.bcidaho.com.
Critically, there is a *chain* of CNAMEs:
bcidahofoundation.org
-->
www.bcidahofoundation.com
--> bcidahofoundation.com
It does not seem to make much sense for Exim to rewrite to an
intermediate point in the chain - yet that is what it does.
All taken together, it seems fairly conclusive to me that this is
unintended behaviour.
Regards,
Max.
