From: Chris Drake
Sent: Wednesday, July 07, 2004 1:58 AM
I don't see why we should help anyone sending mail from a
dynamic IP. _Most_ people on dynamic IP's are not capable
of running MTA's.
Like Will said - there's no way to tell what is or is not a dynamic IP
(and especially not with any reliability strong enough to use such
3rd party guesswork as a rule for erasing other peoples emails!) so
this whole debate is pointless.
Not at all! There are dynamic IP DNSBL's and you can construct regexp's
that are good at discerning dynamic IP pool addresses. IIRC, the EasyNet
dynamic IP list, when it was still around, consisted of submissions from
ISP's. Using a DNSBL does not "erase" any email, rather it is used as a
rejection tool. Each rejection causes a DSN, so the sender knows their
message was not delivered. Liberal acceptance policy followed by
post-acceptance content filtering will unavoidably result in real email
being discarded with no notice to the sender. This is a far worse outcome.
ISPs themselves know their dynamic's, so they can set up their SPF
records accordingly, so the problem is fixed by the only people who
actually do know what is dynamic - that's *exactly* what SPF is *for*.
That's what they're supposed to do, and this will be a great help. However,
since not all ISP's have adequate staff and not all ISP's are competently
managed, it would be prudent to continue to use dynamic IP DNSBL's for the
foreseeable future.
Remember that Kiwi RBL idiot who added some people into his RBL simply
out of spite? He's not the only one who does this - but he did get
sued, lost, and had all his assets confiscated to pay damages, which
included his house. There's a really simple lesson to be learned
here: "Be nice to people".
There are all kinds of people in every field of endeavor. Just like ISP's,
some DNSBL's are run by idiots and some are run by competent, hard-working,
responsible people. Pick the latter and you'll be fine. Taking a position
like "most DNSBL's are run by spiteful jerks" makes as little sense as "most
ISP's are run by incompetent greedheads".
--
Seth Goodman