Re: Unusual spam recently - hummm - postprocess
Quoting David Stanaway (david@stanaway.net):
> My mail system has a number of users, and I prefer to let the recipient
> decide what is spam.
There's a minor problem with this, about which more below.
> Some list servers such as yahoogroups (May it rot in pieces) have the
> annoying behavior of deactivating your subscription on hard bounces
> from MTAs so whenever a list I am subscribed to with lax attachment
> policies gets a worm, and I hard bounce it with mime-header-checks, I
> get deactivated. So this is just one example of hard bouncing spam not
> being a great system wide policy right now (Unless you don't like your
> users :P).
Bouncing spam at all, in any way, is irresponsible admin behaviour.
Consider: Essentially all spam forges as much header information as
possible, and the newer generation even forges the envelope return-path
data. Therefore, if you bounce spam, it is almost 100% guaranteed to
be sent out to a forged address -- a party (extant or not) that did not
send the original spam in the first place. In effect, you are
generating _additional_ spam with each and every such bounce.
However, if your system is able to determine _during the SMTP session_
that the mail is unwanted (as spam or for some other reason), it can
issue a 55X Reject error and refuse delivery, instead of accepting the
mail and then having to make the poor choice between /dev/nulling the
received mail and issuing an almost certainly inappropriate bounce
message.
Smarter and better remedies are possible during SMTP time, than they are
after delivery. A number of other steps are possible, beyond what I've
mentioned.
And, of course, by the time your users have a chance to apply their
judgement on the matter, the MTA has already accepted the mail and
handed it off to an LDA or MDA -- so the opportunity is lost.
--
Cheers,
Rick Moen Bu^so^stopu min per kulero.
rick@linuxmafia.com
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