No C1alis taablets, please.

I'm wondering why, 30+ years since the invention of email, we should still be struggling with spam?

Is it impossible to create some sort of open system of validating signatures? Or perhaps an ISP-based trust-level that would allow someone like me who has been sending spam-free email from the same account for 10 years to have a better rating than someone who has just opened a new account?

The ISP's could then filter out mails below a certain trust-rating threshold and place the oneness on the sender to sort out their account if it goes into a negative rating.

On my end, I could filter mails below a certain trust-rating, rather than trying to come up with complex rules to catch them.