On the other hand, surely it would be considered best practice to have the PTR, A, and hostname used in HELO/EHLO match - and be usefully identifiable.
Um.. Don.. so you're saying that
because you've implemented a policy that rejects email based on
the contents of the PTR, that this is Telecom's fault and they
need to 'fix' it?
Which 'we' are you referring to and what 'discussion' was there?
Since when does NZNOG get to create an operational consensus of
that nature and then blindly assume that everyone will implement
it?
Broadcasting the issue on NZNOG would seem to be inappropriate;
this isn't a fault, this is collateral damage of a policy decision
you've chosen to make. I doubt that nzvanlines.co.nz would be the
only sender affected, but the impact would seem to be on your
customer. You've made the decision to do this; live with the
consequences or change your approach.
The IP of the nzvanlines.co.nz MX record has a valid matching
forward/reverse pair - which is the basic reputational check many
MTA's perform - the fact it contains suggestions that it might be
from a residential-grade connection is not something _I_ would
choose to use when attempting to filter spam; (been there;
onceuponatime SORBS attempted to run a blacklist that identified
dynamic IP address ranges. Persistent false positives meant that
this was eventually a lost cause.)
There are plenty of ways to reduce your spam-count, this wouldn't
seem to be a smart one; In this case NZ Van Lines would need to
decide if making wholesale changes to the way they deliver email
to the world is worthwhile based on their inability exchange mail
with your platform, and your customer needs to decide if the
disruption to their email service is worth the cost of the measure
that's been put in place. And you need to decide whether it's
worth the time and energy and potential loss of customers, should
they decide to move to a service provider who can effectively
filter spam without blocking legitimate email for what seems to be
a fairly inappropriate reason.
Mark.
On 10/09/13 22:17, Don Gould wrote:
From:<gillian.halkett@nzvanlines.co.nz>
SIZE=50696 Tue 2013-09-10 15:27:37:
[126020:1] <-- 250 2.1.0 Ok Tue 2013-09-10 15:27:37:
[126020:1] --> RCPT
To:<jenna@christchurchapartments.co.nz>
Tue 2013-09-10 15:27:38: [126020:1] <-- 553 5.7.1
<222-154-247-46.adsl.xtra.co.nz[222.154.247.46]>:
Client host rejected:
AUTO_[A|X]DSL We aren't accept direct connection not from
dedicated SMTP
servers. Please use your internet provider SMTP Server.
Tue 2013-09-10 15:27:38: [126020:1] --> QUIT
We're rejecting mail from nzvanlines.co.nz because they're
running their smtp server on a service with a|x|vdsl in the ptr
record.
I think we've had this discussion on list before, and iirc we
decided that we just get providers to update ptr records, but
I'm a bit scared to ring L1HD and ask for a ptr change.
Is there an admin on list from Telecom who can work with your
customer to fix this for as I doubt it's only us it's impacting?
D
--
Don Gould
31 Acheson Ave
Mairehau
Christchurch, New Zealand
Ph: + 64 3 348 7235
Mobile: + 64 21 114 0699
Ph: +61 3 9111 1821 (Melb)
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