Google has started automatically blocking emails sent by bulk senders who don’t meet stricter spam thresholds and authenticate their messages as required by new guidelines to strengthen defenses against spam and phishing attacks.
As announced in October, the company now requires those who want to dispatch over 5,000 messages daily to Gmail accounts to set up SPF/DKIM and DMARC email authentication for their domains.
TLS has become too easy to acquire for it to have any effect, I’m afraid. Didn’t Chromium remove the padlock signifying HTTPs connection due to just that? That it doesn’t really mean anything anymore in terms of illegitimate websites (still obviously crucial against MitM)?