I have to agree that a fine per email would be good (California has a law on the books with penalty info) but enforcement or collection would be difficult.
If you've viewed email headers the first received line (coming into your own mail server) I believe can not be faked. All other received lines can be faked. To look up IP's of the source coming to your mail server you will find that most will originate from (1) poor countries (especially APNIC ip groups), (2) from states with predominance of poor people, or (3) from IP's of hosting services that don't care about giving service to spammers.
(a) It may be difficult to identify the actual sender (who may use a dial up service or may access another person's internet connection via insecure wireless LAN or similar), (b) some countries (or states) may not have spam laws or may not respect other country spam laws, and (c) language differences may cause difficulty.
Multiple causes and issues make proof, enforcement, and collection, etc, all difficult.
It is my belief that most IP's in use today are of the IPv4 configuration, such as 184.108.40.206 and I had heard that IPv6 would be forthcoming with a larger number, not sure how many other "digits" would be added, but just by adding one extra group such as abc.220.127.116.11 if the beginning "new portion" of "abc" was to be country specific then all existing ip numbers that a country might have under the old IPv4 system could be retained by that country plus they would gain a lot more usable ip numbers, but the ideal result would be that countries could be identified by their own group.
Consider the aspect of abc for US being 001, Canada 002, Mexico 003, England 004, Japan 005, China 006,.... room for 256 countries (000-255). I believe that would allow almost all countries to have their own "group" (if not enough for all countries to have their own, then a few small countries could share a group with another). If the IPv6 number configuration were not "abc" as in my example, but as "abc.def" then instead of 256 groups there would be 64k groups.
Currently with IPv4 countries may have a huge mixture of IP numbers and the
80-88 group of IP's mostly in Europe shows countries are quite intermixed, likewise for IP's in the APNIC (Asia) group.
Under the new IP system it would be "just like" a County-Code designation for the telephone system.
The great difference would be that with IPv6 implementation that people could configure their email client or mail server to allow receipt of email only from certain countries or could selectively block an ENTIRE country. Simple and easy control of spam. No relatives in Japan and no reason to get email from there the entire country could be blocked from a person's email. Likewise this new IPv6 system where the beginning would be country specific would allow the same control to be added to websites.
If your personal site or business web site would not be doing business with Taiwan (as example) then that entire country could be blocked from your site thus eliminating harvesters etc from that country. The countries that you could allow could be those of your own country or intened audience and for email you could allow your own country and countries that respect your antispam laws.
Limiting email to your own country (and others that respect your antispam laws) would make it easier to enforce existing laws and to collect from violators.
As for the aspect of proving identity of the sender based on originating IP numbers a good part is that "dial up service" providers through courts can tell who the login ID was and in the US telephone records could show who dialed that dialup number (most people don't know that local calls are also recorded on a central office data tape), thus it "could" be possible to trace origination of access via a dialup access to a person's telephone number. Conversely, if a spammer with a wireless laptop drove through a neighborhood and found an insecure LAN/wireless system for access then proof becomes another matter.
Curious: Does anyone have any additinal information about the future of IPv6 IP numbering? Would it be configured to be country specific, as I gave in my example? Any expected date for implementation?
I would think that just the addition of some extra "routers" at the head of each ISP or network that would handle the identity of either "abc" or "abc.def" would be the simplest addition that could make such a change work.
It would surely put a stop to most spam and make it easier to deal with the remaining offenders.