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

[Glenn Stone]

On Tue, Jul 31, 2007 at 11:01:44AM -0700, Jules Agee wrote:
>Glenn Stone wrote:
>>> 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.
>
>I use postgrey too... some of the senders you listed do understand
>retry, they just don't always retry from the same IP address, so
>postgrey doesn't recognize it as a retry. Still, as you mentioned, the
>number of problematic systems are few and the manual whitelist requires
>very little maintenance after the first month or two.

Amazon is the only one that (according to the comments in
/etc/postgrey/whitelist_clients) actually retries, it's just that they use a
unique sender ID (sort of a reverse VERP) every time, which of course
confuses postgrey.  The rest of them that I mentioned, according to the
comments at least, treat "451 Try Again" as "Go, ah say, go'way kid, you
bother me."   

Now, the other itch I may scratch on this at some point is a mechanism to
easily and quickly can greylisting while you're doing something you know is
going to generate an email from *somewhere*, and then, if it's really spiff,
throw a log entry, then once the email is received, search the email logs,
look at everything past the log entry, show it to you, and give you the
opportunity to pick which client to drop in the permanent whitelist,
re-enabling greylisting into the bargain.  (Sort of the moral equivalent of
undoing one's chainlock in order to get the pizza in the door.)  

Pizza, hmmm, ain't it getting close to lunchtime?

-- Glenn