Ian P. Christian wrote on 2009-07-18:
> I urge you, and everyone else running an MX to just outright reject
> mail from hosts without rDNS - there's no excuse for mail server
> admins not to do this, and people not being strict means spammers can
> get away with more on botnets.
>
> The stricter we all are, the better.
A quote from fresh message to the Russian-language exim-users list
http://exim.org.ua/pipermail/exim-users/2009-July/007287.html :
| у многих маленьких компаний с которыми мы
| работаем - нет PTR-записей для IP-адресов почтовых серверов.
I translate:
| Many small companies we work with haven's PTR records for
| IP-addresses of mail servers.
Then the poster asked how to whitelist.
In my experience, I was given a shell account for setting up a
mail autoresponder (for requesting parts of a mailing list archive)
on a machine with static IP-address without PTR record,
the small company which owned the machine hadn't control over PTR records,
the (large) ISP couldn't care less.
I greylist mail from hosts without rDNS. I also deny all mail from
China and Korea. The set of these two measures is quite effective.
