Rich Kulawiec <rsk(_at_)gsp(_dot_)org> wrote:
On Mon, Jul 06, 2009 at 11:39:25PM -0400, Bill Cole wrote:
Large cheap and free mail providers understand the advantage they get
from their scale in not needing to do as well with egress filtering as
smaller mixed sources of mail. There is very little risk to them of
missing 95% of their outbound spam, as long as they never drop legitimate
outbound mail and keep their outbound legitimate mail volume large enough
that it is hard for many sites to treat their mail as presumptive spam.
This is true, but still there is in practice a _large_ variation in
percentage of spam spewed by the "large" email providers.
And this in a nutshell is why so many "accountability" proposals,
while curious/interesting academic exercises, are dead-on-arrival in
the real world: these providers are TBTB (too big to block),
"Blocking" the whole "domain" is not the only trick in our bag...
they know it, and so no matter how many different technologies are
deployed which repeatedly tell us what we've already known for years
(e.g. "Hotmail sends enormous quantities of spam") nothing useful will
happen as a result -- until/unless widespread refusal of traffic comes
into play.
"Hotmail sends enormous quantities of spam" isn't a very useful
factlet. Nonetheless, it does allow some email receivers to at least
graylist some Hotmail servers if the envelope-from isn't on a whitelist.
More useful is something like, "Hotmail MTA #49 is sending more spam
than usual right now: more severe graylisting might be called for."
Or, your reputation service might say, "We're concentrating our
pressure on Hotmail MTA #49 right now: please give it a hard time."
The introduction of reputation services creates options for getting
the attention of the folks who maintain the MTAs of the large email
services.
If we insist on a world without reputation services (or ePostage),
Rich is correct that only "large" email receivers will be able to make a
dent in the practices of "large" email senders.
:^(
--
John Leslie <john(_at_)jlc(_dot_)net>
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