"Seth Goodman" <sethg(_at_)GoodmanAssociates(_dot_)com> writes:
1) Do we really want the preferred deployment Unified SPF to enable people
to violate their ISP's AUP's? This is hardly adoption incentive for ISP's.
Feeling a rare bit of sympathy for ISP's as well as my own inbox, I don't
see why we should help anyone sending mail from a dynamic IP.
To me the idea of having a permanent connection (leased line DSL,
cable etc) and dynamic IP is anathema. Dynamic IP is fine for dial-up
connections (where the IP address of the dial-in port is fixed and the
customer gets the IP address associated with the port into which (s)he
connects) but makes no sense for always-on. The ISP has to have at
least as many IP addresses as customers, so why not allocate static
addtresses? Most people would not consider running an MTA on a dial-up
link. So if all ISPs were to provide static IP addresses for DSL and
cable customers it would simplify the problems for all concerned. It
would also help if ISPs were to do an 'about turn' and rather than
prohibit customers with 'vanity' domains from running their own MTA,
encourage (or even require) customers to run their own MTA when using
a 'vanity' domain. This would simplify the SPF (classic or unified)
records as well as providing better authentication and
accountability. If you are running your own domain, you should not be
forced to use the ISP's MTA with all the problems that brings.