Date:        Sun, 22 Feb 2004 08:44:43 -0600
    From:        seebs@plethora.net (Peter Seebach)
    Message-ID:  <200402221444.i1MEihNr028277@guild.plethora.net>

  | Your ISP gives you an address which resolves to
  | <mumble>.example.com;

No they don't, my "ISP" gives me a link, and some address space, and
that's it.   It resolves to nothing.   They give me this link and address
space for free, they have no reason whatever to start doing any extra
work, maintaining DNS servers, delegating (very small) pieces of
IN-ADDR.ARPA name space, or anything else.

  | you set sendmail to HELO as example.com.
  | No other name seems relevant to this; we're talking about envelope senders,

No, you're not.   If you don't understand that, you really shouldn't be
talking at all.   The envelope sender is something totally different.

You can look at this mail if you like, after passing through a couple of
systems at home, it exits to the net via an unnamed relay (no PTR record).
Yet the envelope sender address is perfectly valid, and gets bounces back
to me.

  | not what might or might not be in your From line.

Which is something else yet again.

PTR records are increasingly obsolete, and rather than attempting to
find more absurd ways to attempt to enforce their use, we should be
abandoning them wholesale.   They're unnecessary.

What's more, this cannot possibly serve to stop spam, other than perhaps
a little in the short term.   There is not, and cannot be, any technical
solution to spam (since spam is simply e-mail).   Whatever is done to attempt
to stop spam, the spammers will work around - after all, they're getting
paid to get the spam delivered - they have a real incentive to make it
work.

Give up on all technical "fixes"  - simply allow spam to overwhealm people.
Then the incentive for non-technical fixes will rise, and in that area,
there are things that can be done, and will be effective.

kre

ps: I'm not exactly sure what all the fuss is about - the amount of spam that
either comes through, or pretends to come through, netbsd lists, is
still negligible.