Re: EarthLink spamBlocker - how rude

From: Vernon Schryver (vjs_at_calcite.rhyolite.com)
Date: 10/03/04 

Date: Sun, 3 Oct 2004 09:23:28 -0600 (MDT)

In article <2sa4n5F1imsopU1@uni-berlin.de>, J.O. Aho <user@example.net> wrote:

>> According to various people that *I* have talked to, the text
>> contained in SMTP 5xx reject responses isn't even preserved or sent
> > back to the original sender by many/most/all Microsloth mail servers.
>> So if the poor schmuck who sends you mail (and who is not already on
> > your whitelist) has the misfortune to be behind a Microsloth mail server,
>> then if you are rejecting mail from unknown/un-whitelisted senders at
>> the SMTP level... with clearly worded 5xx reject messages (telling him
> > how to respond to get himself onto your whitelist)... then he *will*
> > get back an undeliverable bounce message, replete with all of the
> > humanly-indecypherable DSN gibberish, but *without* the text of your
> > lovely 5xx response! (Is THAT like totally fucked up, or what?)
>
>As being quite ignorant about ms based software, does this only affect 5xx
>messages, or all messages including 4xx ?

4yz messages are rarely seen by the original sender of the message
until the sending MTA (mail transfer agent) stops trying to retransmit
the message and returns it to the sender. When that happens, the 4yz
message is at least as likely to be truncated or lost entirely as a
5yz message. If it is not truncated to unintelligibility or lost
entirely, it will be mixed with lots of cybercrud that most system
administrators and practically no end users can decode.

You can test this for yourself by signing up for free accounts at
Hotmail and elsewhere and sending mail to addresses that you know
will be rejected during the SMTP transactions.

(Anyone using a C/R system who does not use a free provider to see how
it looks from outside is an idiot. I think the same of people who
used to use those #$%$%$#@! telephone "screening" devides that demanded
a DTMF password before they would ring, including my relatives.)

For years Hotmail lost all SMTP status messages. Then they fixed that.
As of a year or so ago, the fix was fun. They evidently didn't clear
the buffer in which they captured the status message, so that if your
message bounces back to your Hotmail mailbox from an SMTP server with
a short 5yz string, it was likely to be extended to perhaps 100 bytes
with fragments of 5yz strings from other bounced mail messages.
I wouldn't be surprised if they are still doing that craziness.

Vernon Schryver vjs@rhyolite.com