Roy wrote:-
RS> Again I ask - am I missing something about the way SPF can be used
RS> to fight spam ?
I think the fundamental point you're overlooking is that spammers are
not stupid. In fact - they're very very not stupid. Look at all the
"smarts" in the payloads of the new breeds of spam, they've overcome
blacklisting, overcome content filtering, and generally adapted in
near-real-time to every hurdle placed in front of them.
SPF is *not* designed to prevent spam. If SPF gets in the way of any
spammer, they'll bypass it or adopt it: you can bet your bandwidth
they're not going to let it block them.
The short answer is - every point you made about how they "might"
thwart your anti-spam efforts: they will employ. If you've any
experience selling stuff online via credit cards and the associated
fraud, you'll realize that these people don't even pay for whatever
they buy, so it's "not even" the "cost of a condom" for them to buy
whatever temporary resources they need.