Re: Every spam is sacred
On Sun, 15 Jun 2003, Mathieu Roy wrote:
> Santiago Vila <sanvila@unex.es> a tapoté :
>
> > I called Mathieu simplistic because he was talking in terms of "bad ISPs",
> > "good ISPs". I bet that most ISPs do not have their main SMTP servers as
> > an open relay, because otherwise they would have serious connectivity
> > problems with the rest of the world.
>
> But you are indeed also talking in terms of "bad ISPs" and "good
> ISPs", even if you did not write these words.
No, there is no such thing. DSBL list individual IPs. They do not
list "ISPs". How many times do I have to repeat this?
> You are betting that most ISPs are careful about spam issues, what we
> can easily call "good ISPs" (term I did not used) or "decent ISPs".
> You are proposing to block/tag mails that come from some ISPs,
No, forget about ISPs.
> so you are actually considering these ISP as the bad ones.
No, it's each individual IP the one which might be "good" or "bad",
not the entire ISP.
See, ISP "foo" may have well configured SMTP servers which are not
open relays and everybody in such ISP (except a lot of spammers and
some Unix people) use them to send email. No problem with this.
But a bad user (probably using Windows) may get a virus or have a
badly unconfigured software installed which makes his machine to
become an open relay. As soon as spammers discover this, his machine
will be abused.
So it is logical for other ISPs not to accept mail *directly* from
this machine if they verify it's an open relay, since the normal
traffic from this ISP comes from the good main SMTP servers, which are
not open relays, and it's what people are "expected" to use.
[ Some people even block smtp connections just because they come directly
from a dial-up IP, to force you to use your ISP's SMTP server, but I'm
not advocating for anything like that ].
That's why people use DNSBLs which list open relays, as a defense
against abuse, not as a way to punish "bad ISPs". Most of them already
know that an open SMTP relay will be abused as soon as it's discovered,
it's the customers of such ISP the ones likely to run open relays.
Of course there might be ISPs whose main SMTP servers are open relays,
but that would be an economical suicide. I would not want to be a
customer of such ISP, because a lot of people would block my mail.
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