That doesn't make what they're doing okay. To see why, imagine that they instead blocked access to all email services except their own, since spam is a big problem.
That's basically what domestic ISPs do. You will probably find that outbound traffic on port 25 is blocked, because all of your pwn3d inadequately-patched Windows machines are spam cannons now.
I’ve come to treat residential ISPs as basically a transit for HTTP. As someone else in the thread pointed out that’s all that 99.99% of customers care about, and unfortunately you’re talking about a lowest common denominator here.
