On 5 May 2014 20:51, Murray S. Kucherawy <superuser@xxxxxxxxx> wrote:
On Mon, May 5, 2014 at 12:46 PM, Murray S. Kucherawy <superuser@xxxxxxxxx> wrote:How? I'm fairly certain it does neither.
Sorry, I missed that there were later replies.The SMTP state machine is not changed by DMARC any more than SPF or others changed it. It doesn't add any new states, verbs, parameters, or anything else. DMARC sits at least two "layers" above where SMTP operates. As with any number of other filtering systems, it can influence SMTP's final DATA reply, but that's hardly unique or even unusual.
It aims to change the behaviour of Internet Mail as deployed.
Whether you want to claim that this is formally extending SMTP, per-se, or not is really something of a moot point - there is certainly an intentional, large, effect on the deployed protocol. Arguing whether this fits the letter of some particular definition smacks of lawyering to my mind.
Dave.