According to the BBC, South Korea’s Internet and Security Agency is asking all ISPs to block all e-mail sent from anything but “official” e-mail servers. The idea is to block spam, but will it really accomplish this goal?
It’s not like this is a new idea. The Anti-Spam Technical Alliance proposed it as a best e-mail practice for ISPs in 2004. It’s a simple idea. If an ISP blocks the default Simple Mail Transport Protocol (SMTP) port, Port 25, from sending e-mail messages, users will be forced to use their ISP’s mail servers. This, in turn, the theory, goes will magically stop spam.
ISPs loved this idea. Today, most ISPs already ready block port 25. AT&T, Comcast and Verizon to name only three already do this. In practice what this means is that unless you have a static Internet Protocol (IP) address chances are you must use your ISP’s official e-mail server to send mail out.
Yep, it’s already a popular, frequently implemented idea. Too bad it doesn’t work.