Massive Growth in SMTP STARTTLS Deployment
When we posted in May about the state of STARTTLS deployment, we had no idea that we would see such significant changes to email encryption across the industry in just a few short months. We previously reported that only 28.6% of our outbound notification emails were successfully encrypted and passed strict certificate validation (58% if you count opportunistic encryption). Since STARTTLS encryption requires both sides to deploy it, we encouraged others to take the next step. As a result of recent changes by major providers, most notably Microsoft and Yahoo, 95% of our notification emails are now successfully encrypted with both Perfect Forward Secrecy and strict certificate validation.
In addition to thanking these service providers for implementing best practices and allowing stronger encryption to take hold, we'd like to encourage any remaining providers to deploy STARTTLS as soon as possible.
Michael Adkins is a Messaging Integrity Engineer at Facebook.
