Indeed, in more detail (which I omitted for simplicity), these checks are performed in a series of headers, the last of which is the From: header. I think the “envelope-from” is either the first or the second in this 5-point list. That said, there are a lot of implementations out there that do not respect that and treat the From address as the sender whose honesty must be verified. Every time I send mail to a mailing list from my own domain, due to DMARC I get back several reports of SPF and DKIM fail, mainly because the mailing list messed up something.
> On 29 Mar 2017, at 18:32, William Herrin <b...@herrin.us> wrote: > > On Wed, Mar 29, 2017 at 11:25 AM, Grant Taylor via NANOG <nanog@nanog.org> > wrote: > >> Every SPF implementation I've seen has checked the SMTP envelope FROM >> address /and/ the RFC 822 From: header address. >> > > Hi Grant, > > The gold standard, Spamassassin, does not. Indeed, the message to which I > reply was scored by spam assassin as "SPF_PASS" even though you do not > include NANOG's servers in the SPF record for tnetconsulting.net. > > Regards, > Bill Herrin > > > -- > William Herrin ................ her...@dirtside.com b...@herrin.us > Dirtside Systems ......... Web: <http://www.dirtside.com/>
