Damn. Looks like Google is going to enforce DMARC for email sent to Gmail now for even more sites than ever before.
DMARC is a combination of a dodgy message signing scheme (DKIM) combined with an entirely stupid and misguided way of trying to advertise the valid origins for a domain's email (SPF).
This may help cut down spam a wee bit, though I doubt it (most spam I still see is DKIM signed at least any may even be fully DMARC compliant)
However it's also going to bounce a lot of legitimate email in the near term.
Unfortunately they are not considering PGP-signed messages as "authenticated".
#smtp #email #spf #dkim #dmarc #gmail #bigbrother #pgp