Re: namedroppers, continued

> From: Paul Vixie <paul(_at_)vix(_dot_)com>
> ...
> i am reminded by this thread that the most powerful force on the internet
> continues to be a single voice saying that something cannot be done.
No, what you are seeing is something that has always been true on the
Internet.  Anything that depends on the actions of third parties who
will not gain by it takes a long time.  To hope for something to take
off, it must be worthwhile from the start.  This proposal costs many
people and organizations now (new software) and forever (MX, .forward,
mailing list, and mobile hassles) and benefits no one for at least
the first year or so.

What's in it for the owners of the domains most commonly (not really)
"forged" into Mail_From values, the free mail providers?  The main
effect for them is that they both be forced to process more out-going
mail and see their user base reduced.  Many users who now use a free
mail provider Mail_From value would either have arrange to send through
the free mail provider or switch to a return address based on IP
bandwidth provider.

What is the difference in the short and medium term between your
proposal and teaching your MTA to check that one of the A records for
the reverse DNS name of the SMTP clients contains the IP address of
the client?  A major difference is that you can install this check
today without waiting for anyone else to do anything.  We all (well,
some of us) can name a raft of reasons why such checking is a bad idea
in general, but you could easily do it only for the domains you think
might eventually provide the new DNS RR and that have a significant
(so called) "forgery" problem, the free mail providers.

For that matter, why not simply blacklist any and all mail with From
values pointing at free providers.  With a white list of your friends
who use free providers, that is an extremely effective spam filter.


Vernon Schryver    vjs(_at_)rhyolite(_dot_)com