On Feb 20, 2007, at 1:51 PM, [EMAIL PROTECTED] wrote:
On Tue, 20 Feb 2007 12:57:54 -0800, "Brian Keefer" <[EMAIL PROTECTED]>
said:
Now they've evolved to using botnets and the vast majority of spam
comes from such systems, so the bandwidth costs are gone and the
hosting costs are pretty much limited to how much they have to pay
the criminals for the botnet C&C passwords. It's not a matter of
cost any more, it's a matter only of efficiency. If they make more
money by spending some cycles to resend, they'll do it. Your average
spammer might be pretty dumb, but the people who are writing their
tools are usually pretty clever. I wouldn't underestimate them.
OK, now please propose a solution.
Obviously if anyone had that and cared to commercialize it, they
would be a billionaire (judging by cisco's nearly $1bn acquisition of
IronPort).
I don't think there is any one, final solution for a problem that's
allow to exist because of a flawed system. SMTP just wasn't designed
for a hostile Internet and any fixes bolted on are prone to work-
around or severe usability problems that limit adoption. There's
always going to be a race between spammers and anti-spam techniques
until enough people get sick of SMTP that they design a new way to
send messages across the Internet.
If your site cares a lot about blocking spammers and not legitimate e-
mail, shell out for a top-of-the-line commercial solution and keep
paying maintenance to get updates for fighting new spam techniques.
If you don't have the budget, it isn't important, or you oppose
spending money for such a thing, use off-the-shelf tools like what
OpenBSD has available.
There isn't one right answer, only varying degrees of suitable. If
you're using something that works great, keep doing that for as long
as it works. The main point is that you have to be prepared to adopt
as spammers do.
Brian Keefer
www.Tumbleweed.com
"The Experts in Secure Internet Communication"
