Re: fixing insecure email infrastructure (was: Re: [eweek article] Window of "anonym

[Stephane Bortzmeyer <bortzmeyer () nic fr>]

On Wed, Jan 12, 2005 at 10:59:43AM -0500,
 Steven Champeon <schampeo () hesketh com> wrote 
 a message of 98 lines which said:

> 1) any legitimate mail source MUST have valid, functioning,
> non-generic rDNS indicating that it is a mail server or
> source. (Most do, many do not. There is NO reason why not.)

Since this list is NANOG, it is reasonable that it has a North
American bias but remember the Internet is worldwide. I do not know
how it is in the USA but there are many parts of the world where ISP
do not have a delegation of in-addr.arpa and therefore cannot pass it
to their customers. (It is also common to have many levels of ISP, so
you need to go through many layers before reaching the RIR.)

Requesting rDNS means "I don't want to receive email from Africa".