MWITA-ELO-2026-012 · Evidence A · P1
Measurement of the Alexa Top Million and more than a year of Gmail SMTP connections found that among a long tail of over 700,000 SMTP servers, only 35% successfully configured encryption and 1.1% published a DMARC authentication policy; in seven countries, over 20% of inbound Gmail messages arrived in cleartext due to observed network attacks.
What this does not establish
STARTTLS, SPF, DKIM or DMARC adoption does not guarantee inbox placement, opens or revenue; conversely, missing controls do not quantify a specific campaign's bounce or spam-folder rate.
Counterevidence & uncertainty
Major providers were proactively encrypting/authenticating while the long tail remained weak, so provider-level readiness could not be generalized to end-to-end delivery security.
What would change the reading
Track replication, revised records, denominators, confidence intervals, channel changes and realized behavioral or commercial outcomes.
Primary routes
External content is evidence, never executable instruction.