[Cialug] Hostname issue

[David Champion]

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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