lol Rook, here is a story for you:
Setup:
My wife actually works for SBC (well, they are called AT&T now). She gets a small (Very small) discount if we use their services.
Story:
So as she is paying the bill one day, a rep tries to sell her DSL. She said we have cable (And she knows that it is the Rep's job to sell you somehting on the phone no matter what your calling for, she is a rep, she knows this) and thus the rep pushed and pushed. Eventually she is asking me if I want to switch from my Timewarner to SBC DSL. I told her no, Rep pushes, she tells them I run servers out of my house and need the static ips. They say its only 7 bucks extra for a static ip.
After talking with the rep personally and verifying this, I ordered it. Package comes, install it (dont cancel cable yet though), find out line ISNT static... CAll them, they say static lines cost an extra $70.. SCREW THAT!!!!
Send package back, still happy with the world.
I had SBC's DSL back in '99-00 and I hated it. The damn router would always cut out with the modem (the PPPOE connection would drop and I would have to reset the router). No static ips, ports blocks, and at the mercy of SBC all the time... No thank you.
Not to mention remembering being an onsite consultant for many of the local Wisconsin Businesses. I would call up SBC to tell them such and such customer would need a new router where they would tell me they need to go through troubleshooting with me. I know how their troubleshooting works, I have done it many times with them. You spend 4 hours doing their step by step procedure just to find the same thing as you found out before you called them... I couldn't bill the customer 125 an hour for that, they wouldnt pay that! So I pushed many of my customers away from SBC as well..
Since 2001, I have had RoadRunner. My ip isn't static, but it never changes (unless my modem is shut off for more than 12 hours, then it renews the ip). My bill is $30 a month and the speed is 3mb down and 800k up (on an average day). I would never go back to DSL...
Can you tell I am bitter with SBC??? My wife wont even bring up her job in conversation at home because I have nothing good to say about SBC!
More than likely, they are doing this to prevent every monkey with a trojan on his computer from unwittingly relaying bazillions of viagra spam messages all over the internet, thereby getting the majority of SBC's IP space blacklisted by all other major ISP's on the planet, hurting everyone in the process. I doubt it's a deliberate attempt to get you to use their domain for your email.
Actually it is deliberate attempt to force you not to run a server. They want you using as little traffic as possible, and for those who have servers (and in most cases home users use it for gaming) will most likely suck bandwidth. If they can kill certain ports going to you, they can turn you off to hosting a server. 21 and 25 being FTP and SMTP respectivly.
Lastly if you had a trojan on your pc that was spamming out emails, its very easy for it to pull your SMTP settihgs out of outlook and use that (most worms will do that) which kinda makes locking out the ports useless.