You may not have noticed, but you can’t connect to port 25 from your SBC DSL connection. So, if for example you have a hosting site and you are trying to send an email from Outlook to your smtp server, the email will not leave the Outbox. I haven’t updated my account profile with SBC in a while, so they didn’t notify me of this change.
Overall, I like it. It is worth the tiny amount of pain here to let the world know that very very little spam will come from SBC’s DSL network. I have no doubt that more large ISP’s will finally do this.