Re: [anti-spam-wg] Domains with MX set to localhost
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To: der Mouse mouse@localhost
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From: Markus Stumpf maex-lists-spam-ripe-anti-spam@localhost
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Date: Thu, 12 Jan 2006 18:25:40 +0100
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Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys
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Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=testkey; d=space.net; b=RgfpIY7+uAqA/XH+9q/VkUpYI5+gGDrAUR+pKEtKTZwgaavY4tnp/gV6H3jv7qlZ ;
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Organization: SpaceNet AG, Muenchen, Germany
On Wed, Jan 11, 2006 at 10:50:38AM -0500, der Mouse wrote:
> How is the second one possible? An MX record isn't capable of
> containing anything *but* a FQDN.
In theory ;-)
I've seen more than once records like
example.com IN MX 10 10.0.0.1
i.e. an IP address instead of a FQDN in the RHS of the record and mailservers
even connecting to the correct host :)
DJB's dnscache even has the "feature" to map A queries for IP adresses to
IP addresses:
$ dig 10.0.0.1
;; ANSWER SECTION:
10.0.0.1. 1w14h2m40s IN A 10.0.0.1
Since we use it on our caching DNS servers for the mailservers (I was
really sick explaining customers 5-10 times a week, why their mails won't
reach the destination, as specified by clueless admins) I don't see
problems with that any longer, but I am sure those kind of records are
still there.
\Maex
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