Perhaps exim could have a special catch for this to produce a message
that indicates what the trouble is?
Eg, if it finds an MX for which the domain doesnt exist, check the
target of the MX record against a regex that will match a dotten quad,
if it matches, include some text in the error like
"Cannot send mail to domain xxxxx.xxx: It seems like the DNS operator
for this domain has installed an invalid MX record with an IP address
instead of a domain name. To work properly MX records MUST be domain
names, NOT IP addresses"
On Wed, 3 Jun 1998, Philip Hazel wrote:
> Date: Wed, 3 Jun 1998 09:11:28 +0100 (BST)
> From: Philip Hazel <ph10@???>
> To: Tim Patterson <tim@???>
> Cc: Alan Mitchell <bythesea@???>,
> Omar Shahine <shahineo@???>, exim-users@???
> Subject: Re: [EXIM] Mail delivery failed: (My ISP's problem?)
>
> On Tue, 2 Jun 1998, Tim Patterson wrote:
>
> > not sure, but guessing its the use of an ip instead of
> > a domain name.
> >
> >
> > exim 1.62 reports
> > x@??? is undeliverable:
> > all relevant MX records point to non-existent hosts
> >
> > nslookup -type=mx lists.boingo.com
> >
> > Non-authoritative answer:
> > lists.boingo.com preference = 50, mail exchanger = 206.159.213.31
>
> You are correct. The actual MX record is
>
> lists.boingo.com. 3600 MX 50 206.159.213.31.
>
> but there is no such domain as 206.159.213.31. This seems to be a common
> mistake, as I seem to see one of these every couple of months. The RHS
> of an MX record is a domain, not an IP address. Domain names consisting
> of digits are perfectly valid...
>
>
> --
> Philip Hazel University Computing Service,
> P.Hazel@??? New Museums Site, Cambridge CB2 3QG,
> ph10@??? (sic) England. Phone: +44 1223 334714
>
>
> --
> *** Exim information can be found at http://www.exim.org/ ***
>
>
--
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http://www.exim.org/ ***
