Back in May, the social network did an assessment of how many SMTP servers its productions system successfully negotiates TLS encryption with, and the results were the following:
- 76% of unique MX hostnames that receive Facebook emails support STARTTLS, an extension that offers a way to upgrade a plain text connection to an encrypted one
- 58% of Facebook notification emails are successfully encrypted
- 74% of hosts that support STARTTLS also provide Perfect Forward Secrecy.
These new numbers are manly due to major providers such as Microsoft and Yahoo making the change.