On Mon, Sep 14, 2009 at 10:39 AM, <alxgomz@???> wrote:
>> Is long as the IP address reverse resolves, it will be the third
>> group. If the host does not reverse resolve, then there will only be
>> two groups. In my log parsing script, I use this:
>
> Yes that's true, but do you accept mail from hosts that doesn't reverse have
> lookup? If so you should not.
In Asia, it seems a bit more common to have non-reverse resolving mail
servers. Larger Asian sites (and worldwide in general) such as hinet
or yahoo do it right, but it's surprising to me how many there are
that do not reverse resolve.
> Even your own clients (relay networks) should have PTR records in some forms
> like "stuff.like.reversed.ip.dyn.dial.in-addr.arpa"
I greylist anything that doesn't reverse resolve. There is no
threshold for successful greylist completions, so if a host does not
have reverse resolution, the greylist penalty is imposed on every
message. They get no reward for successful deliveries.
--
Regards... Todd
