Kov?cs Albert:
> On Tuesday, March 10, 2015 1:42 PM, Wietse Venema <wie...@porcupine.org>
> wrote:
> >> I'm not sure how one (type of) dns query is a performance concern,>> and
> >> another is not, see below.
>
> > You see no performance difference between querying a small number
> > of well-operated DNS servers that are chosen by the local sysadmin,
> > versus random DNS servers all over the Internet that are determined
> > by the sender's IP address?
>
> this isn't exactly what i wrote :-) Obviously querying PTR records may
> take some time. However, smtpd also needs the PTR record to perform some
> DNS tests, so sooner or later you need the query.
If everything smtpd did was OK for postscreen, then we would
not need postscreen.
Wietse
