Re: [dmarc-ietf] Revisiting the Race Condition in draft-crocker-dmarc-sender-01

[Joseph Brennan <[e-mail]>]

I've been running email servers for 25 years. My number 1 priority is that
legitimate mail gets through. Stopping the bad stuff is very important but
not number 1. Does DMARC causes legitimate mail to fail? Yes, so to me it's
a fail.

I can understand the transactional mail case, as I stated in
previous messages. The burden is on the businesses implementing DMARC
protection to inform customers to give their real end-point email addresses
and not any vanity forwarding services. Any two sides can agree between
them on some optional additional security measure. It's a good thing.

For general end-user mail? It's a bad thing. It will cause email to fail,
and it will cause people not drinking the DMARC kool-aid to implement crazy
non-standard things with From headers to make email work the way it
should work without crazy workarounds. I see no reason that the DMARC
standard should not spell out explicitly the use case that it is intended
to meet, and recommend against using it for other use cases.

I realize that this was said ten years ago (or whatever it was) when
yahoo/aol began abusing DMARC. But see how that went. The problem was not
really DMARC at all, it was abuse of DMARC.


-- 
Joseph Brennan
Lead, Email and Systems Applications
Columbia University Information Technology