Performance Issues - PTR Records

Wed Nov 9 22:07:10 UTC 2011

In message <41F6C547EA49EC46B4EE1EB2BC2F341849F82D4BE8 at EXVPMBX100-1.exc.icann.o
rg>, Leo Vegoda writes:
> Mark Andrew wrote:
> 
> [...]
> 
> > > That said though the PTR->forward->PTR check is a proper check and a
> > > really great way to figure out if the source SMTP host was actually set
> > > up with at least some admin doing it the right way. If they can't be
> > > bothered to set that up, why should you bother to accept that mail, or =
> a
> > > better choice, just score it a bit negatively at least.
> >=20
> > Which only works as a filter because ISP's decided to prevent home
> > users from putting valid PTR records in the DNS for their own
> > machines.  It has nothing to do with clue or knowlege. =20
> 
> Some do but some don't. I seem to remember a very nice little web interface=
> for setting reverse DNS when I used xs4all's service in the Netherlands.=20
> 
> Regards,
> 
> Leo

But many do.  As I said the ability to set up PTR records has
*nothing* to do with the clue level of the administrator.  It has
everything to do with what the ISP will let you do.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org