> STARTTLS adoption is well over 90% now. That makes me wonder if it would be reasonable for a diverse group of email providers (large and small) to announce t

> STARTTLS adoption is well over 90% now. That makes me wonder if it would be reasonable for a diverse group of email providers (large and small) to announce that they will add a 1 hour delay to emails received from or sent to servers that don't support STARTTLS. Perhaps each year that delay could double, until those non-compliant services became basically unusable. To make this change even less controversial, users could be given the option to whitelist certain email addresses so that exceptional use cases could still be supported.