There are "no-spam" laws. They are, at best, modest successes. For those of us who receive hundreds of spams daily, and/or have manage mailers which receive many more, the laws are miserable failures.
The general problem is the considerable cost in going after spammers. It is almost impossible to recover more than a fraction of these costs, even when there is complete success in prosecution and seizure of the spammer's ill-gotten gains.
Don't forget that when spammers get money, it goes straight through their nose (or in other non-recoverable means). For every big time spammer with a million dollar house there are lots of small fry living in his mother's basement.
Technically, this is impossible with the current mechanisms used by Internet mail. Nothing short of a complete redesign from the ground up will accomplish it.
Anything less is just a band-aid. We have had such mechanisms as PGP and S/MIME for years.
An effort to create a new Internet email infrastructure would be extraordinarily expensive and complex. It would make the conversion to TCP and SMTP in 1983 look trivial by comparison.
It would put legions of programmers and protocol engineers on the gravy train for many years. The people who you hear groaning about the possibility are the vendors who *sell* the products. The programmers who *write* the products (and thus are *paid* by the vendors) are salivating at the prospect of a multi-year pork-feed that would make a lamphrey look like a piker.
The new email infrastructure will also give the world email postage stamps. And this time, it won't be just governments who get a cut of the profits. The biggest objection to SMTP in the SMTP vs. X.400 wars two decades ago was that SMTP's fundamental design made it impossible to impose email postage stamps. You can bet that the new redesigned Internet email won't have that problem.
Guess who pays for all of this.
Be careful for what you wish. You may get it. And there are plenty of people who are quite happy to provide it to you (*ka-ching*!).
-- Mark --