[leafnode-list] WARNING: Stupid Challenge-Response trespass to cause unsubscription!
Matthias Andree
ma at dt.e-technik.uni-dortmund.de
Sat Nov 13 03:29:21 CET 2004
Please note:
if you are using a challenge-response antispam system, you must make
sure that
1. it looks at the envelope sender and allows wildcard white listing
2. you whitelist the list envelope sender address (check the Return-Path
of several list messages, the sender address varies - VERP!)
3. it does not challenge list mail, bounces, bulk mail.
Challenge-Response systems will easily fall prey to address forgery and
annoy the wrong person (the forgery victim) with the challenge.
Don't use them.
I will unsubscribe people who use such broken C-R systems without
advance notice, and I will not, in the future, send a notice that I
unsubscribed or disabled delivery to the user.
Note that I will also unsubscribe people who use broken "vacation" or
"out of office" auto-responders such as those in common Groupware, for
instance Exchange. These, too, MUST send mail to the envelope sender
address and use a NULL return path, and MUST NOT be sent in response to
list mail.
IFF you are getting automatic responses to YOUR list post, please bounce
or forward the mail with all headers to me off-list (to
leafnode-list-owner at dt.e-technik.uni-dortmund.de), I'll then check the
facts and disable the offender's subscription, and I will ban repeat
offenders.
I am *annoyed* by half-baked mail "solutions", common Windows mail
software with its standards non-compliance, Challenge-Response antispam
systems, delayed bouncers (qmail!) and SPF systems fall into this
"half-baked" category and will render mail useless faster than spam
would.
Please respond off-list. Reply-To: header is set.
--
Matthias Andree
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