RE: [exim] DNSBLs

On Thu, 2005-03-24 at 09:02 -0500, David Brodbeck wrote:
> I've seen multi-user systems blacklisted [by Spamcop] when a
> single user sent a single message that looked spammy.

Spamcop tries to measure the amount of legitimate traffic from a host.
I don't know how, but logs of (failed) DNS lookups could serve as a
simple and neat solution. just make sure to ignore the lookups done by
spammers ...

anyway, you can't hope to have extensive stats on every mail host.

> It's entirely subjective,

no, it's partly automated and objective.

> and it probably wouldn't be that hard for someone to forge
> submissions to get any system they wanted listed.

I don't think this is true, you would need to send quite a few reports
to get one of the larger mail hubs blacklisted.

> When this happens,
> there's no way of getting the system removed, either, other than to just
> wait for it to expire off the list.

that's not my experience. on the two occasions we were blacklisted, the
response from Spamcop to our query (submitted via the web interface) was
prompt and friendly. takes an hour for the DNS to refresh, though.
--
Kjetil T.