As expected, spammers keep becoming smarter.
The way to stop spam is to eliminate its value, not its source. Spammers send this crap to make money. So who pays them?
If it's a business, then that business is doing a pretty poor job of analyzing its marketing success rates. Just because you can "reach" the whole world, doesn't mean it's worth the money: everyone will delete your "flyer" and make a mental note to hate your brand for eternity (and tell their friends). So, one step is to convince businesses that spam not only won't win any customers, but it will most definitely lose some.
The other likely payer is the receiver, when receiving scam spam. Scammers aren't paying anyone to send spam, they're expecting a payoff when some idiot gives them what they "legitimately" asked for. Again, the solution is education, but a different kind: people need to be informed about how to recognize E-mail scams (apparently some people really can't). Even if one guy in a million sends his life savings, it justifies the effort of spammers.
Maybe novice computer users need a license to drive their mail client, as if it were a car, and I'm only half kidding. They can harm at least themselves if they don't know what they're doing. This education would solve other problems as well.