[SLL] [SLL} Re: Anti-spam methods

[Glenn Stone]

On Mon, Jul 30, 2007 at 12:56:19PM -0700, Dan Wilder wrote:
>On Sun, Jul 29, 2007 at 03:09:39PM -0700, Glenn Stone wrote:
>> 
>> On the other hand, I have found greylisting, which is almost but not quite a
>> challenge-response mechanism which is *built into SMTP*, to be quite
>> effective.  Most well-behaved MTA software will retry just after the
>> greylist timeout, or, if not, within an hour... 
>
>Or after 4 hours or after 8 hours ...
>
>Works OK if your mail is not time critical, and if none of it comes from
>people operating clueless MTAs that don't understand retry.   I believe
>there may still be some of those.

Postgrey, which is what I use, comes preseeded with what they hope to be a
comprehensive list of them as are still braindead, which include Yahoo
Groups, Southwest Airlines, Ameritrade, Debian (!!), and Amazon (by way of
trying to embarass them into fixing things).  So, yeah, there are such
things, but they're actually reasonably well-known, and one would presume
that updates to the package would include whitelist updates as well.

Oh, and Mitch, if you happen to be listening?  mxlogic.net doesn't retry
either.  (Of course, presumably you'd have your upstream filter providers
whitelisted already in the .local file...)

-- Glenn