There are many who say the only way to truly eliminate spam is to change the way e-mail works. However, changes to the most fundamental standards behind sending e-mail over the Internet—SMTP and Domain Name System—are a long way off and will likely only reduce spam, not eliminate it.
At this point, changes to SMTP and DNS that would significantly limit the flow of spam are years away. Most proposals are only in working draft form or are ideas that originate from vendors and have not yet been submitted to the Internet Engineering Task Forces working groups for consideration. The Anti-Spam Research Group, a working group within the IETFs Internet Research Task Force, is the main industry body studying proposals for managing spam.
Most proposals involve creating a way to validate that the sender of a message is an authorized sender of e-mail over the Internet. Validation methods include authentication, modifying mail exchangers, using DomainKeys (a proposed method of authentication from Yahoo Inc.) and standardizing C/R (challenge/response) systems.
Two fundamental problems with SMTP contribute to the volume of spam.