Do you really not care whether people accept your mail?

["John R Levine" <[e-mail]>]

On Mon, 13 Mar 2017, Carsten Bormann wrote:
> The most likely outcome is that local admins will “upgrade" our mail 
> system by turning off IPv6.  (We have had IPv6 deployed for some 18 
> years now.)

On Mon, 13 Mar 2017, Philip Homburg wrote:
> Getting mail delivered to gmail over IPv6 works most of the time without
> ever setting up SPF or DKIM. Gmail does seem to be the single most
> unreliable mail server that I know of, mostly due to their attempts
> to be more strict on IPv6.

As I hope everyone knows, receiving mail requires orders of magnitude more 
work than sending it.  Even 20 years ago before spam was an issue, 
recipients had to receive it, route it, store it somewhere, filter it with 
sieve or procmail, and provide POP or IMAP for the recipient to collect 
it.  These days, with 90% of mail being spam or worse, there's another 
magnitude of work in trying to separate the real mail from the flood of 
junk.  Or try this thought experiment: how hard would it be to send a 
million messages a day from your laptop (easy), and how hard would be be 
to receive and deliver a million messages a day on that laptop 
(impossible.)

The point of authentication schemes like SPF and DKIM is to make it easier 
for recipients to tell that your mail is from you, so they can treat it 
differently from the spam.  Everywhere else, the response is OK, I would 
prefer that people get the mail I send them, I will set up authentication 
because it is not hard (SPF takes about 5 minutes), and it helps the 
people who are handling my mail with the mail system they are paying for.

I can also assure you from many conversations with large mail providers 
that you will increasingly find that recipients will conclude that if you 
can't be bothered to authenticate your mail, they can't be bothered to 
deliver it.  It's their mail system, they get to do that.

In the IETF, for some reason, people take a perverse pride in offering no 
help whatsoever to mail recipients, even when that help costs them 
nothing, and then snark and whine when the recipients have trouble dealing 
with the unauthenticated mail.  I don't understand why, but I really wish 
people would stop.  Nobody is impressed that your mail system does exactly 
what it did 20 years ago, and it gives outsiders the impression that the 
IETF is a bunch of out of touch sociopaths.

R's,
Johh