On Wed, 11 Nov 1998, Andromeda wrote:
> At 12:39 11/11/1998 +0000, [someone] wrote:
> >The best solution I've found to that at the moment is the :blackhole:
> directive
>
> Where do I find this? I've improved my own anti-spam measures by using the
> sender_reject and sender_reject_recipients directives with an lsearch.
>
> In addition to RBL and sender_address_relay, I think I have a very solid
> system to kill spam in the future.
There are three approaches to spam which really shouldn't be debated here
(I am sure there are more appropriate lists).
(1) Filtering and blackholing:
Using exim filter files an other techniques it is possible to
blackhole unwanted mail. One advantage of this is that if the filter
file is in a user readable place on the mail delivery system, then
users can opt into or out of the filtering. The filtering could also
be set to deliver mail to a particular folder, etc. Lot's of
varients.
Advantages: Gives the end use the most control. Only suspect spam
messages are actuall filtered, probably has the best hit rate of the
three options.
Disadvantage: Takes work (or smart automation) to maintain the
filter, so is the hardest of the three to implement. MOST IMPORTANT:
This makes life easier for spammers and the sites that support them.
Spammers are only stopped by complaints. This eliminates complaints.
Sites that support spam are only discouraged by blocking. This makes
it easier for spam hosts. If most sites followed a
filtering/blackholing policy spam would grow immensely.
(2) Site blocking (RBL, maintaining local lists, etc).
Advantages: This is the ONLY of the three general schemes which
actually puts pressure on the spammers and the sites that support it.
It is very easy to implement (depending on active you want to be with
maintaining a local blocking list)
Disadvanges: Doesn't really stop all that much spam. Does block
legitimate mail from blocked sites, annoying local users. This sort
of policy has to be very carefully explained to local users.
(3) Ignore it.
Advantages: Very easy to set up and maintain.
Disadvantages: Can't cite some policy when local users say "We need
to do something about this"
My personal belief is that responsible sites on the network have the right
and the responsibility to do (2). (1) is selflish (it protects local
users, but makes life easier for spammers to engange in more theft of
network services). (3) has it's merits. (Crnafield's position is still
being debated internally).
I don't want to open the debate about this here. I only want to point out
that what you are looking at for your site is a shift from (2) to (1), and
that such a shift in policy should be thought through carefully.
-j
--
Jeffrey Goldberg +44 (0)1234 750 111 x 2826
Cranfield Computer Centre FAX 751 814
J.Goldberg@??? http://WWW.Cranfield.ac.uk/public/cc/cc047/
Relativism is the triumph of authority over truth, convention over justice.
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