Most of the VPS providers have been implementing variations of this for a few years now. Most of them will not block ports on accounts created before a certain date and will open the ports for people that open a ticket and state they will not be sending UCE and are responsible postmasters that will secure their mail servers inbound traffic and accepting an agreement that if they abuse it or let someone else abuse it their account is gone. Seems more than fair to me. It's a nice alternative to having to say, "and this is why we can't have nice things." We can have nice things.