Re: [nznog] Xtra mail admin and ptr records...

On Tue, Sep 10, 2013 at 05:31:36PM -0400, Joe Abley wrote:

On 2013-09-10, at 17:25, Mark Foster wrote:

...

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?

It's not an uncommon policy. People even tried to document it in the IETF, although they didn't get very far (I think the idea is too ugly to imagine hanging it on the otherwise pristine walls of the ivory tower).

Drawing Xtra's attention to it does not seem like a bad thing. Using NZNOG as the primary way to contact Xtra mail admins seems a bit unfortunate, especially if it's necessary :-)

thing is that ptr just says ADSL - it doesn't say that it's dynamic. And looking at Spamhaus it's not listed in SBL, or PBL. Spamhaus PBL records pretty accurately on policies for IP blocks. If anyone on ADSL is a lesser user, it's akin to the APNIC blocking that some people have been known to do because "lots of spam comes from China", even though the majority of spam comes from the US. I understand wanting to block IP's from ADSL users who haven't opted out of policy blocking, but I'm not even sure that blocking of lack of reverse DNS is a positive thing - Recently there's been quite a few IPv6 configurations without working IPv6 reverse DNS which can lead to losing some mail. Personally I've noticed the bulk of spam coming through from hotmail, yahoo, and other free email providers with all the right boxes ticked, but completely malicious users. That said I block using Spamhaus which blocks the majority of the low hanging fruit, without giving excessive false positives. Ben.