Marc Perkel wrote the following on 7/12/2007 7:19 PM -0800:
>
>
> Meng Weng Wong wrote:
>> On Jul 12, 2007, at 9:15 AM, Marc Perkel wrote:
>>
>>> Need a rule written to take advantage of this trick and this could
>>> be a major breakthrough in white listing.
>>>
>>> Here's what it needs to do:
>>>
>>> 1) Take the IP of the connecting host and do an RDNS lookup to get
>>> the name.
>>> 2) Verify that the name that was looked up resolves to the same IP
>>> address.
>>> 3) Look up the name in this dns list ===
>>> example.com.hostdomain.junkemailfilter.com
>>> 4) if it returns 127.0.0.1 - it's ham

>>
>> I'd like to suggest that where the domain publishes SPF, we use that;
>> where it doesn't, we use your algorithm.
>>
>> I recently coded up a very similar approach; I posted about it on the
>> SPF and Karmasphere mailing lists. Here is the original message:
>>
>>

>
> SPF is rather useless. Spammers can publish SPF records.

Hmmm, and that said in response to the author of SPF... Oops!

Bill