Need DNS records help for single server (and IP), and multi-domain mail server.

[Grant Taylor]

On 08/23/2017 07:50 PM, Reindl Harald wrote:
> which means again: additional dns lookups while ip-adresses and ranges
> are done with a single lookup

Yes, it does mean additional lookups, which there are a finite number of.

> besides it's not true because SPF has nothing to do with PTR and they
> won't get https://en.wikipedia.org/wiki/Forward-confirmed_reverse_DNS
> how is that related to the topic at all?

It's my understanding that some SPF implementations will do a reverse
DNS lookup on the connecting IP and test the name from the PTR record
against the SPF record of the purported sending domain.

Thus the ability for Evil Spammer to arrange for the PTR record of their
server to return a name that is allowed via SPF.



-- 
Grant. . . .
unix || die