Author: Alan J. Flavell Date: To: Exim users list Subject: Re: ignore_spammers, was Re: [exim] Sporadic unroutable address
On Wed, 4 May 2005, Tony Finch wrote:
> On Wed, 4 May 2005, Alan J. Flavell wrote:
> >
> > Meantime, Tony Finch presented an alternative method, in which the
> > spammers are dealt with in the ACL by doing local dnsdb-type lookups
> > and then looking-up the resulting IP against appropriate blacklists.
> > Reasonable enough, though it duplicates work that's evidently being
> > done in the lookuphost router anyway. But I think maybe it's
> > something we ought to try, nevertheless.
>
> It depends whether you want to be able to send email to them, or let them
> contact postmaster.
As I said at the time, Tony, we let mail through to postmaster before
we do the "verify = sender" stanza, so that's OK.
I actually prefer it that our users can't send mail to those
addresses, at least not from our mail server, considering that we're
going to reject any reply we get. If the users are annoyed by that
then they sure know where to come. (There's hardly ever anyone knocks
on the office door other than to say "I've got a problem" and expect
us to solve it by yesterday...)
I really don't put addresses into our ignore_spammers list lightly.
It's only done after severe provocation, and study of the relevant
anti-abuse registers. Basically, as I said, it's used as a means of
dealing with professional spammers who have a certain range of IP
addresses, but who register tens of thousands, in some cases hundreds
of thousands, of domain names to use in their envelope-sender
addresses, on some kind of conveyor-belt scheme, far too fast for the
RHSBL blacklists to keep track of them. But their IP ranges sure show
up in Spews and Spamhaus.
