[Cialug] Hostname issue

Josh More jmore at starmind.org
Tue Nov 25 10:11:38 CST 2014


That didn't happen when I tried a -x earlier, though it is happening
now.  However, this is also happening:

$ dig mail2.gilstermarylee.com

;; QUESTION SECTION:
;mail2.gilstermarylee.com.    IN    A

;; ANSWER SECTION:
mail2.gilstermarylee.com. 6159    IN    A    216.138.60.195


So there's that issue too.


I say to nuke the zone file from orbit.  It's the only way to be sure.   ;)


(Or you could fix the forward lookup for mail2.glistermarylee.com ... whatever.)



On Tue, Nov 25, 2014 at 10:02 AM, David Champion <dchamp1337 at gmail.com> wrote:
> Dude, the PTR isn't the problem.
>
> $ dig -x 66.186.99.236
>
> ...
>
> ;; QUESTION SECTION:
> ;236.99.186.66.in-addr.arpa.    IN      PTR
>
> ;; ANSWER SECTION:
> 236.99.186.66.in-addr.arpa. 85405 IN    PTR     mail2.gilstermarylee.com.
>
> ;; AUTHORITY SECTION:
> 99.186.66.in-addr.arpa. 85405   IN      NS      ns2.clearwave.com.
> 99.186.66.in-addr.arpa. 85405   IN      NS      ns1.clearwave.com.
>
> ;; ADDITIONAL SECTION:
> ns1.clearwave.com.      171805  IN      A       199.30.61.2
> ns2.clearwave.com.      171805  IN      A       199.30.63.2
>
>
> ...
>
> -dc
>
>
> On Tue, Nov 25, 2014 at 9:56 AM, Josh More <jmore at starmind.org> wrote:
>
>> $ dig barracuda.gilstermarylee.com MX
>>
>> On my system, this shows no DNS entry for barracuda.gilstermarylee.com
>>
>> The fallback SMTP host (A record) points to 75.149.203.77
>>
>> A reverse on 75.149.203.77 points to visionitnow.com, which doesn't
>> match the forward.
>>
>> As Jonathan points out, a reverse on 66.186.99.236 isn't set up.
>>
>> There is also no SPF or DOMAINKEYS entry for 66.186.99.236
>>
>> So, the problem is that the receiving mail server doesn't think you're
>> a legitimate sender (don't blame it, I wouldn't either).
>>
>> To fix it:
>>
>> 1) Add an MX record for barracuda.gilstermarylee.com that points to
>> the barracuda devices's external interface, which is probably
>> 66.186.99.236.
>> 2) Add a TXT record for barracuda.gilstermarylee.com that lists the
>> SPF rules.  (http://www.spfwizard.net/ can be helpful here)
>> 3) Consider a TXT record for DOMAINKEYS. This isn't so important these
>> days, but you might as well look into it.  (
>> https://www.socketlabs.com/domainkey-dkim-generation-wizard/ may help)
>> 4) Review the A record for barracuda.gilstermarylee.com and see if you
>> really want it pointing to 75.149.203.77.  I think this is a wildcard
>> and probably not what you want.  Odds are, it should be set to the
>> same as the MX record in step 1.
>> 5) Recognize that SMTP sucks and it shouldn't take 15 years of
>> routing, SMTP and DNS experience just to set up a freaking server.
>> Outsource your email to someone else and wash your hands of the whole
>> stinking mess of it.
>>
>> -Josh
>>
>>
>> On Tue, Nov 25, 2014 at 9:46 AM, Jonathan A. Kollasch
>> <jakllsch at kollasch.net> wrote:
>> > On Tue, Nov 25, 2014 at 09:38:09AM -0600, L. V. Lammert wrote:
>> >> Trying to assist a friend in fixing an issue with their email system, ..
>> >> they appears to be using a Barracuda appliance (per hostname), yet it
>> >> appears to not be sending a valid hostname:
>> >>
>> >> ================
>> >>
>> >> Nov 23 03:38:37 mx2 postfix/smtpd[5951]: NOQUEUE: reject: RCPT from
>> >> unknown[66.186.99.236]: 450 Client host rejected: cannot find your
>> >> hostname, [66.186.99.236]; from=<rhayden at gilstermarylee.com>
>> >> to=<lvl at omnitec.net> proto=ESMTP helo=<barracuda.gilstermarylee.com>
>> >>
>> >> ================
>> >>
>> >> I do know they are switching providers, but I do not think that would
>> >> affect the issue. Any suggestion on how to troubleshoot this problem?
>> >
>> > This sounds like 66.186.99.236 doesn't have reverse DNS records.
>> >
>> >         Jonathan Kollasch
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