Re: [dmarc-ietf] ESC for Failed DMARC Validation

[Дилян Палаузов <[e-mail]>]

Hello Alessandro,

if a site wants to emit X.7.30, it will find a way to do so (sometimes or always).

I prefer an ESC over an SMTP service extension, since I consider ESCs as much easier to implement and otherwise both
options are the same.

Regards
  Дилян

On Sat, 2019-08-03 at 18:27 +0200, Alessandro Vesely wrote:
> Hi,
> 
> On Fri 02/Aug/2019 23:27:48 +0200 Дилян Палаузов wrote:
> > these are already now two ESC: 2.7.30 and 5.7.30.  X.7.30 means in both cases, that DMARC validation failed.
> > 
> > For a domain with policy p=reject; pct=0 the mail is delivered (250 2.7.30), despite failed DMARCр and for a domain with
> > p=reject; pct=100 when DMARC failed and the mail is rejected (550 5.7.30).
> 
> A message can be rejected as soon as a reason to do so it is found.  That
> principle uniquely defines the reject response.  The accept response cannot
> collect what every filter thought about the message.  To act as you propose,
> the DMARC filter should be granted the special privilege to set the text of the
> response in any case.
> 
> On Courier-MTA there's no API to support that.  Do Postfix or Sendmail provide
> one?  I doubt, since SMTP doesn't attach a special significance to the text of
> the response, except for the 220, 221, 251, 421, and 551 reply codes.
> 
> 
> Best
> Ale