Yesterday, I questioned whether legislation can stop spam. Today, I found and article discussing whether technological solutions can stop spam. The level of optimism in the article seems about on par with the level of success that technology is having in blocking spam: it helps, but the battle is far from over.

One proposed solution addressed in the article is the idea of replacing the SMTP protocol, which is how most email is routed around the internet today (it goes by SMTP from the sender to your mailbox on your server, and then by POP3 from there to your mail reader). SMTP was designed before anyone had imagined spam, and thus wasn't built to make spamming difficult. In particular, it is possible to conceal the real source of spam by inserting false information in email headers about where the message came from. This makes it nearly impossible to track some spam back to its source to either block it or punish the sender (assuming there are laws against what they've done).

Replacing SMTP completely would be a major undertaking and would not happen overnight. Once a new protocol is created, it would either have to be closed to people without software that supported it (including both email client and server software), or gateways would need to be created to inject SMTP mail into the new system, and to get mail sent through the new system back into the SMTP-based system.

Perhaps in the beginning, such gateways could have liberal policies for what they would accept from the SMTP side, and gradually close down over time. For example, at first they might accept everything, but later, only accept mail from whitelisted email addresses, and then perhaps at some point, close down completely. Such a system should enable people who want to use strict rules for accepting email from an SMTP gateway to enforce their rules even if the SMTP mail got into the system through someone else's gateway.

Of course, all of this discussion presupposes the creation of a better protocol. I've read comments here and there from people thinking about it, but no strong contenders have yet emerged and garnered enough attention to make it look like such a solution is coming any time soon.

I'll leave discussion of other technological solutions to another day. For now, I'll just say that replacing SMTP...gradually...sounds like a good idea to me.