Here is a case where RFC's conflict.
RFC5321 in Section 5 [
http://tools.ietf.org/html/rfc5321#section-5] states:
"The lookup first attempts to locate an MX record associated with the name. If
a CNAME record is found, the
resulting name is processed as if it were the initial name.*"*
To add to the fun, a couple lines further into the paragraph states that:
" If an empty list of MXs is returned, the address is treated as if
it was associated with an implicit MX
RR, with a preference of 0, pointing to that host."
So technically, every A record must be treated as a capable mail
exchanger even if there are no MX records.
We could just axe all the MX records.
On Wed, May 27, 2015 at 3:59 PM, William Lewis <kg6baj(a)n1oes.org> wrote:
> (Please trim inclusions from previous messages)
> _______________________________________________
> Don't get me wrong. I'm not saying people should ignore the RFC1035
> standards. I'm just saying its possible. The one's I'm aware of are all
> companies using 'In-House' mail systems designed to either keep the mail
> staying in-house, and/or prevent outside mail from getting in.
>
> But, as pointed out, this group should be following the RFC1035 standard.
>
>
> ----------
> Wm Lewis (KG6BAJ)
> AMPR Net IP Address Coordinator - Northern and Central California Regions
> (A 100% Volunteer Group)
> (530) 263-1595 (Home/Office)
> ______________________________________________
>
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> At 03:48 PM 5/27/2015, you wrote:
>
>> (Please trim inclusions from previous messages)
>> _______________________________________________
>> On Wed, May 27, 2015 at 3:41 PM, William Lewis <kg6baj(a)n1oes.org> wrote:
>> > Where you say "Owners, please update them with a proper hostname
>> instead of
>> > the literal IP address." I would like to point out that it is entirely
>> > possible to have an IP address that has no HOSTNAME assigned to it at
>> all.
>> > The most common are used for mail. I use 2 that are setup this way for
>> > security reasons.
>>
>> MX records must point to a hostname. Here's a good description of why:
>>
http://serverfault.com/a/663122
>>
>> But the bottom line is: it's the spec.
>>
>> Tom KD7LXL
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http://hamradio.ucsd.edu/mailman/listinfo/44net
>>
>