From: Tony Earnshaw (tonyebilly.demon.nl)
Date: Thu Sep 02 2004 - 14:36:33 CDT

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Hi!

Playing with a new, largish (1100+ user) Postfix 2.1.4 site just before
it enters "real" production.

Honing the cutting edge, greylisting, smtpd_mumble_restrictions, sender
callouts etc. It's fscking brilliant. But.

Postfix is more-or-less cutting out 99% of the spam and virus before it
ever gets to amavisd-new/Sophos or dspam. Even with my own lax HELO and
smtpd sender restrictions. What getting the buggers are greylisting,
sender callout and 4 RBL checks.

Here's the rub. Bonafide Windows client idiots first "ehlo" with our own
domain. "EHLO barlaeus.nl". O.k. no sweat. The goods don't come until
later. They don't make any use of "ehlo", they just go further (this is
the gdl greylist daemon, absolutely brilliant software):

_____________________________________________________________________

Transcript of session follows.

 Out: 220 mail.barlaeus.nl ESMTP Postfix (2.1.4)
 In: EHLO barlaeus.nl
 Out: 250-mail.barlaeus.nl
 Out: 250-PIPELINING
 Out: 250-SIZE 10240000
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250 8BITMIME
 In: MAIL FROM: <idiotidiot.nl>
 Out: 250 Ok
 In: RCPT TO: <happinessbarlaeus.nl>
 Out: 450 <idiotidiot.nl>: Sender address rejected: Greylisting in
     action, please try again in a couple of minutes ...
___________________________________________________________________________

They do not try again, ever. They are idiots, but nevertheless probably
potential paying customers.

It's greylisting that the idiots don't understand. On their shitty Windows
client MUAs they see "The server does not like you, go away", even though
what they actually get is "Greylisting in action, please try again in a
couple of minutes ...". They do not understand, since they are Windows people.

Does anyone have any advice here? I'm loathe to cut out greylisting, since it
and the other Postfix weapons are saving us tons of resources. But Windows
idiots are, and will remain just that.

Tx!

--Tonni

--
They love us, don't they, They feed us, won't they,
Oh who will think a boy and bear
Could be well accepted everywhere?
It's just amazing how fair people can be

mail: tonyebilly.demon.nl
http://www.billy.demon.nl

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