[dns-operations] Trustworthiness of PTR record targets

[Doug Barton]

Ignoring that Jim's response was a bit snarky, and also ignoring the 
other responses you've already received, it's hard to answer your 
question without knowing a bit more about what you're up to. However, in 
general:

1. Anyone can put anything in a PTR record. There is no safe assumption 
that the content is accurate.

2. In my experience (which is not thorough, but also not zero) anti-spam 
folks are completely uninterested in what's in the PTR, and generally do 
not do any blacklisting by domain name in the sense you seem to mean.

hth,

Doug


On 03/03/2014 09:26 AM, Stephen Malone wrote:
> Hi Folks,
>
> For PTR records out there that are pointing to domains other than those
> that you control, I’m looking to understand common practice around their
> setup. Two questions:
>
> 1.In general, can I trust PTR records? Is ownership of the target domain
> validated at setup time by ISPs, and if yes, how is this done?
>
> 2.If ownership of PTR targets is not routinely validated, is there a
> risk that the target domain could be blacklisted by anti-spam providers?
>