Re: Commecial vs fairness (was: spam support)
- Date: Sat, 16 Feb 2002 12:54:50 +0100
On Fri, Feb 15, 2002 at 12:18:41PM +0100, Anne Marcel Roorda wrote:
> Educating admins on how to maintain a blacklist if they so choose
> would be a better sollution. Getting them to drop the local blacklist
> and move to one of the several publicly available blacklists would be
> even better.
We are an ISP using publicly available blacklists (a bunch of them)
and subscription-based ones; but we also have our own, at present
containing about 4000 IP numbers or blocks (and also 6000 domains and
4000 single email addresses; but we are discussing IPs now).
The local blacklist is extremely important to us, because it gives
us an easy and fast way to block established spam sources without
going through the effort of submitting nominations to public
blacklists and wait for them to be accepted. We often do that
(Steve knows..), but there are just too many spammers and too
few people reporting, and a day is only 24h.
Moreover, there are spam sources (so called "mainsleaze" spammers)
that no blacklist dares to block, yet they send unsolicited mail
in large quantities. Outfits like pm0.net, Responsys etc. Many
of them change domain every week, so they have to be blocked by IP
if you want to stop their mail.
We bounce all mail with a contact URL in the error message.
Everybody receiving a bounced mail from us knows how to contact us
and negotiate the removal. Having said that, we do not "maintain"
the local blacklist other than adding spam sources, and removing
IPs _on demand_ (after having determined that those IPs are no
longer a spam source).
I believe that several ISPs work in this way, and I expect anybody
taking on a block previously used by a spammer to do quite a bit
of work to have his block removed from local blacklists, even
if the spammer was there years before.
In my opinion the "radioactivity" issue should be somehow addressed
by RIPE (and of course also ARIN and APNIC): after all, by
reassigning a block previously used by a spammer they are
delivering deteriorated goods :-)