mail filtering based on reverse DNS

[Bjørn Mork]

Ignatios Souvatzis <ignatios at cs.uni-bonn.de> writes:

> On Wed, Aug 10, 2011 at 01:19:20PM +0200, Bjørn Mork wrote:
>
>> rev(A) != PTR
>> rev(AAAA) != PTR
>
> In the modern days, where often a lot of services *with their own
> domain names* run on big server machines, it is unreasonable to require
> that forward and reverse resolving agree. 

Maybe.  Still, as this discussion shows, there are those advocating that
as an absolute requirement.

> Requiring any PTR might be ok.

How would that be useful in any way?  A PTR without a matching A or AAAA
record will tell you exactly nothing.


Bjørn