No, you weren't using the service correctly,
IMHO. And you haven't
read your ISPs terms of use, probably.
The best would be to block every port??? If communication between
clients and servers are bad for mail, this must also be true for WWW?
Let's block port 80! This would be the ultimate security solution for
you! But nobody would pay for a service like this! Bad for shareholders
like you ;-)
Patrick Kaell