It's more common than you might think, especially for small regional ISPs
who don't have a large allocation of addresses from ARIN. For DSL
subscribers, my ISP offers a choice of a static IP (private 10.x space)
which routes through a NAT firewall, or a static publicly routable IP for a
small add
Simply telnetting to his box on port 25 reveals there is indeed an open port
with a service willing to accept connections from strangers. If the SMTP
service is configured similarly, then yes, this is very much an open mail
relay begging for spammer abuse.
>is that ip a single machine or a nat'
